Three, two, one, or none.  No matter how many trophies are in Manchester United's possession at season's end, Sir Alex Ferguson is almost certain to invest some of the Red Devils' massive wealth into some great talent this summer.

United have juggled various injuries and off the field issues to maintain the top-seat in the Premier League while staying more than alive in both the FA Cup and Champions League.

Despite a strong campaign in all competitions, though, United have some player-personnel issues to address this summer. 

The Red Devils are going to be looking at bolstering their midfield and defensive options as well as finding a long term replacement for Edwin Van der Sar in goal. 

United will probably end up spending up to £100 million on new talent when the transfer window closes at the end of August this summer, half of which will probably be spent on just one player.

We're going to be looking at five players Sir Alex Ferguson and company should seriously consider signing this summer along with some viable alternatives if United chooses to overlook or ignore such talents. 

Note:  Estimated transfer fees are personal assessments.

5. Gregory Van Der Wiel

Position: Right Back

Current Club: Ajax

Age: 23

Est. Transfer Fee: £10-20 million

Van der Wiel is one of the most in demand fullbacks in Europe right now.  He has established himself as the starting right back at Ajax for nearly three seasons now, while firmly rooting himself into the same position for the Netherlands' national side.

The young Dutch international possesses great pace and strength to go along with solid crossing ability.  Van der Wiel also has incredible stamina and is rarely substituted out of games by club or country. 

He is an emotional player, though, with his hot headed displays sometimes boiling over, earning him unnecessary bookings.  Van der Wiel also needs to work on his tackling, but he usually makes up for it with his previously mentioned speed and strength.

United do have a need for talent on the outside of their defense right now. 

The Red Devils fullback corps currently includes the likes of Patrice Evra, Wes Brown, John O'Shea, and the Da Silva twins (Rafael and Fabio).

However, O'Shea and Brown have struggled with injuries in recent years, with the latter looking poised to leave the Red Devils this summer in order to find more first team opportunities.

Bringing in Van der Wiel will give United a strong and balanced option at right back to go along with speedy wing-back, Rafael Da Silva, and versatile utility man, John O'Shea.

As previously stated, Van der Wiel is in high demand, with Premier League rivals Chelsea also favoring the signature of the young defender. United are going to have to be quite aggressive if they are going to keep him out of their rivals reach, especially since the West London side is no slouch with the check book as well.

Alternatives: United do have Belgian international Ritchie De Laet returning from a series of loan spells at season's end.  He has stated his intentions to challenge Rafael for the starting spot at right back, but he will most likely be used as a defensive cover for the back four if United choose to name him to the 25 man roster for next season.

Outside of England, PSV Eindhoven's Stanislav Manolev is a good affordable option while Schalke's young Japanese international, Atsuto Uchida, is an impressive wing back with a good résumé of club and international experience.

However, if United are not afraid to break the bank, they can go after AC Milan's Ignazio Abate or Real Madrid's Sergio Ramos.  Either player would easily slot into United's defensive scheme, giving the Red Devils one of the best back-lines in club football.

4. Balazs Dzsudzsak

Position: Left Winger

Current Club: PSV Eindhoven

Age: 24

Estimated Transfer Fee: £20-25million

The Hungarian international may not get the attention he deserves since he plays in a smaller league (Dutch Eredivisie) and for a lesser European football power, but he is by far one of the best left-footed wingers in the game right now.

Dzsudzsak has started nearly every game for PSV Eindhoven since officially joining the Dutch side from Debreceni VSC in January of 2008. 

He has 22 goals and 10 assists in 43 appearances in all competitions this season, picking up a lot of the attacking bulk over the last few months because of Ibrahim Afellay's move to Barcelona over the winter.

Dzsudzsak is the ideal winger with incredible pace and crossing ability.  He has a powerful shot to go along with being a solid dead-ball specialist.  Still not impressed?  Well he is also an ambidextrous player who is comfortable attacking from both sides of the field.

United are in dire need of more left-footed attacking talent.  Crossing from the left side of the pitch has been mediocre at best for the Red Devils this season.  Anderson has never looked comfortable out wide, while Fabio and Patrice Evra are of better use when deployed from the fullback position. 

Ryan Giggs still has a lot of gas in the tank at 37, but a player like Dzsudzsak is entering his prime and would be a great long term replacement for the Welsh legend.

Alternatives: The always in demand Ashley Young is the first player to come to mind.  However, United already have great right-footed talent in Nani and Antonio Valencia to go along with the always industrious Park Ji-Sung.

Young will also not come cheap and Aston Villa will probably want a similar player in return on top of any transfer fee paid.  I don't think the Midlands side will be too keen on Bebe or Gabriel Obertan, who have failed to impress when given the opportunity this season.

If Sir Alex Ferguson has no problem with another right-footed forward/winger, then Ashley Young is most certainly their guy.  If not Young, then Udinese's Alexis Sanchez. Schalke's Jefferson Farfan, and Lille's Eden Hazard are all players of similar caliber worth approaching.

Back on the left-footed scheme of things, Andre Ayew is a young and speedy winger who has impressed immensely over the last year for Ghana and French side, Marseille.

CSKA Moscow's Mark Gonzalez is another solid option.  He has been pretty consistent since leaving Liverpool in 2007, but I don't know how open the Chilean international would be towards a move back to the Premier League.

3. Moussa Sissoko

Position: Central Midfielder

Current Club: Toulouse FC

Age: 21

Estimated Transfer Fee: £15-20 million

Sissoko is a young but well-rounded box to box midfielder with spectacular tackling ability and boundless energy.

He is great at winning the ball while being comfortable in both attacking and defensive roles, which well warrants the comparison to fellow Frenchman, Patrick Viera.

Since making his debut back in August of 2007, Sissoko has made over 140 appearances while scoring 20 goals for French side, Toulouse.  Despite a successful young career, he has expressed his desire to move on to a bigger and better things with le Tef currently mired in the middle of the Ligue 1 table.

The holding role at Old Trafford has been a big question mark this season.  Michael Carrick and Darren Fletcher have both signed new long-term deals, but United need to add a solid yet creative midfield enforcer, especially with Paul Scholes yet to sign on for another year. 

United's best defensive midfield option, Owen Hargreaves, has been living an injury riddled nightmare over the last two years and may never take the field in a United shirt again with his current deal expiring this summer.

Sissoko is a similar player, strong and industrious, with no serious injury history, so it's best that the Red Devils snap him up before their rivals do.  He'll also be a great foil for the less aggressive Carrick, while being able to easily partner with nearly every member of United's current crop of midfield talent.

Alternatives: United have been tracking Everton's Jack Rodwell for a while now, but I feel it would be better to bring in a more experienced young player like Sissoko.  Rodwell is still a bit of a raw talent, plus he has struggled with injuries lately. 

Despite Ferguson's admiration for the young lad, he should really wait a bit on Rodwell before investing any serious money into the young English international.

Blackpool's Charlie Adam is another great box to box midfielder entering his prime right now, plus he is left-footed.  As previously mentioned, United need more left-footed talent and the Scottish international is no slouch in that area.

Along with Sissoko, Ligue 1 is loaded with great defensive midfield talent.  Yann M'Vila has impressed for Rennes in recent years, while Marseille's Stephane Mbia is an even more enticing option since he can easily drop into central defense.

Meanwhile, Roma's Daniele De Rossi, a former United transfer target, has hinted at leaving Roma to better his chances of winning some serious silverware.  Another Serie A talent, Slovenian international Armin Bacinovic, a personal favorite of mine, is another great central midfield option who has been spectacular for Palermo this year.

As you can see, if Ferguson feels Sissoko is not to his liking, United still have plenty of strong midfield options from all over Europe.

2. Wesley Sneijder

Position: Attacking Midfielder

Current Club: Inter Milan

Age: 26

Estimated Transfer Fee: £40-50 million

United are severely lacking in creative attacking midfield talent and if they are looking into spending serious money this summer, then they might as well spend it on one of the best playmakers in the world right now.

Sneijder is quick, strong, ambidextrous, and possesses an extremely powerful yet accurate right-footed shot.  He is also one of the best dead-ball specialist in the world and can certainly bend it better than Beckham at times.

The Dutch international has impressed wherever he goes, scoring 81 goals in well over 300 appearances split between Ajax, Real Madrid, and his current employer Inter Milan.

He's no bum for his national side, though, with 21 goals scored in 76 appearances for the Netherlands.  His most impressive display was during the 2010 World Cup in South Africa where he lead the Orange to the tournament's final (sadly losing 1-0 to Spain), scoring five goals along the way.

United's only real attacking midfield options right now are Park Ji-Sung and Anderson.  Park is usually deployed out wide, while Anderson has only impressed in short spurts due to several spells on the sideline.

With fellow diminutive midfielder Paul Scholes contemplating retirement, Sneijder will be a more than perfect replacement if the United legend decides to hang up his boots at seasons end. 

Even if Scholes signs on for one more year, Sneijder would still give United a much needed attacking boost to a well worn midfield corps.

Alternatives: There are quite a few out there.  Tottenham's Luka Modric is the first to come to mind.  Ferguson has always kept an eye on the left-footed playmaker, but the Hotspurs seem well prepared to fight off any interest in their Croatian superstar.

I'm a big fan of Borussia Dortmund's Shinji Kagawa, but the Japanese international is currently out for the rest of the season with a metatarsal injury.  However, United signed a player with a similar injury almost 18 years ago when they bought Roy Keane from Nottingham Forest, and we all know how that turned out.

United are still tracking young Brazilian playmaker, Douglas Costa, who spurred United and several other Western European powerhouses for the open attacking scheme of Shakhtar Donetsk almost two years ago. 

Meanwhile, Christian Eriksen of Ajax is another young attacking talent that has caught the eyes of several big sides over the last year, with the Dutch side dreading the loss of another top young talent.

Finally, Palermo has benefited from the strong performances of the dynamic midfield duo that is Javier Pastore and Josip Ilicic, both being heavily scouted by all big sides.

1. David De Gea

Position: Goalkeeper

Current Club: Atletico Madrid

Age: 20

Estimated Transfer Fee: £20-30 million

Filling out the number one jersey is the biggest area of need for United this summer.  Edwin Van der Sar is closing the curtain on a spectacular career at season's end and finding the perfect replacement between the posts at Old Trafford will be easier said than done.

David De Gea is actually an easy find and hard prospect to overlook.  He's very young, but has made 74 appearances for Atletico Madrid since taking over from the struggling Sergio Asenjo in September of 2009, keeping 22 clean sheets along the way.

The Spanish international is tall and commanding, while possessing great reflexes.  He's stays cool under pressure, which cannot be understated in an attack heavy league like La Liga.

De Gea does need to work on distributing the ball better as well as improving communication with his defense.

However, those are two areas that he can easily advance while training with the Red Devils, especially if Van der Sar stays with United in the form of a coaching role.

Alternatives: Schalke's Manuel Neuer has been at the top of the rumor mill for a while now, but the German international has recently stated his desire to not leave Germany without winning any silverware first.

Maarten Stekelenburg is a great experienced option, but Ajax are going to be hard-pressed to part ways with the Dutch number one.  Hugo Lloris of Lyon has also throw his hat in the ring, but I don't know if United are really considering the French number one.

Igor Akinfeev is another personal favorite of mine since he's strong, commanding, and has pretty much been CSKA Moscow's number one since the age of 17.  However, he seems to have dropped off Ferguson's radar due to the emergence of De Gea over the last 20 months.

Finally, there's Liverpool's Pepe Reina, but United and Liverpool rarely do business anywhere but the pitch.  Despite all the rumors, I just don't see such a move ever taking place.

What About Up Top and the Center of the Defense?

United could improve in both areas, but they are not the priority.

First, United currently have a great trio of forwards in the form of with Dimitar Berbatov, Wayne Rooney, and Javier 'Chicharito' Hernandez. 

Michael Owen has struggled with injury and his contract is expiring, but United have Danny Welbeck, Federico Macheda, and Mame Biram Diouf all coming back from loan spells at season's end. 

The latter two will probably be loaned out again next season, maybe even sold, but Welbeck has impressed with Sunderland this year.

The young English international most certainly improved his chances of pushing for a first team place at United next season.  He'll give the Red Devils a solid left-footed striking option, plus he can play out wide when called upon.

Ferguson and company are tracking Porto's  Rolando, but United have a good group of center-halves in place with Nemamnja Vidic and Rio Ferdinand the preferred partnership in front of the Red Devils goal. 

Ferdinand has struggled with injuries recently, but newcomer Chris Smalling has performed well beyond expectations in his absence.  United also have Jonny Evans, who has been a more than competent cover despite recent struggles.

Wes Brown may choose to move on this summer, but United still have veteran utility man John O'Shea to call upon.  As previously mentioned,  Ritchie De Laet has been impressive while on loan with various sides this season, and looks poised to challenge for a spot on the first team roster this summer.

When it's all said and done, though, United should have quite a few new faces rolling out onto the pitch next season.