Manchester United have done a pretty good job of getting rid of the right players, making naming the team they could have had a difficult challenge.

The rules are as follows: Make an XI of players who have been allowed to leave the club cheaply or on a free transfer, or not had their loans at United turned into long-term deals. 

They have to be active players, and their selection is based on their current level of ability rather than their career peak.

This ridiculously attacking XI would be lined up with four defenders, one defensive midfielder, two attacking midfielders and three strikers, though two of the strikers could drop deep to help link play. 

In truth, not all of these players would be improvements on United's current options, making the "fantasy" aspect of this limited to a couple of key individuals. The rest essentially make up a decent—or at least close-to-decent—option.

Tim Howard

We immediately run into the problem of improving United's current options in goal. Of the choices available, Tim Howard pips Ben Foster and Anders Lindegaard to earn the fantasy No. 1 jersey. 

Loaned to Everton in 2006 and then allowed to sign for £3 million, Howard counts as a player who was allowed to leave cheaply. 

On his metaphorical day, he is capable of making fine saves—as he proved during the U.S.'s 2014 World Cup campaign. He would not oust David De Gea from between United's sticks, though, so he is in the side through convenience rather than true fantasy.

Rafael

With Matteo Darmian's form looking shaky and Antonio Valencia out with a long-term injury, Rafael da Silva would be a superb squad option for manager Louis van Gaal. Instead, he now plies his trade with Lyon, having been sold for £2.5 million.

A section of United's support loves Rafael for his tigerish endeavour and enthusiasm. In 2013-14, Sir Alex Ferguson's final season in charge, he looked to be growing into a superb all round full-back, but neither David Moyes nor Van Gaal ever truly seemed to trust the Brazilian. 

In spite of an excellent turn against West Ham United at Old Trafford last season, he was allowed to leave after another injury-hit campaign. Plenty of United fans would welcome him back into the squad—and indeed the first XI—with open arms.

Patrice Evra

Patrice Evra should still be at Manchester United. 

Perhaps not for football reasons, but certainly because the now-Juventus man talks with as much love for the club as many United fans. Indeed, following Juventus' win over Manchester City on November 25, Evra told the BT Sport interviewer (h/t Manchester Evening News) he was a "red forever."

Even in purely footballing terms, Evra has been much missed. Last season saw Luke Shaw struggle to adapt to his new surroundings, and having the experienced Frenchman to guide him would have been a boon. This season, in the wake of Shaw's injury, Evra would have had plenty of game time. 

This is an example of a player leaving cheaply—for just £1.2 million—who could have made a difference to the club had he stayed.

Nemanja Vidic

Both centre-back positions are troublesome to fill. Nemanja Vidic looked to be past his prime when he left United, and his struggles in Italy have done little to suggest he could improve Van Gaal's back four this season. 

Vidic's inclusion here is a consequence of the paucity of still-high-quality players who have left United in his position and a sentiment based on the service he offered United when he was in their employ. 

Jonny Evans

Few fans are crying out for the return of Jonny Evans, though he did have a good game at Old Trafford in West Bromwich Albion colours back in November. 

The Northern Irishman was a product of the United youth system and showed genuine promise when playing alongside Rio Ferdinand or Vidic when one of them was absent. Once they had left the club in 2014, he struggled to make the step up. Last season, it was clear he had fallen behind Chris Smalling and Phil Jones in the pecking order. 

He is here to make up the numbers, but given how far back his links with the club go, he will be thought of with affection at Old Trafford for a long time, even though he only briefly made the grade.

Paul Pogba

The star of this particular side, and one of the most glaring examples of the one that got away in world football. 

United, crying out for a dominant and creative midfielder, somehow allowed Paul Pogba to slip through their fingers.

Even though their longstanding midfield problem has been thoroughly addressed by Van Gaal's transfer activity, Pogba would still slot straight into United's first XI. 

Seemingly destined to be an important figure in football for a long time to come, Pogba will always elicit thoughts of what might have been from United fans—especially if he ends up playing for one of their Premier League rivals, which does not seem far-fetched.

Shinji Kagawa

Shinji Kagawa's time at Manchester United was not a success. Signed by Sir Alex Ferguson but never truly given centre stage by either Ferguson or David Moyes, Kagawa struggled to adapt to the Premier League away from his clear No. 10 role at Borussia Dortmund.

This season, back at Dortmund, he has been showing a glimpse of what United could have had should they have held on to him. He has five assists in the Bundesliga, more than any United player has managed in the league.

He would perform an important function in this XI as an inside-left forward—not the out-and-out No. 10 position, but it'd be close enough to that for him to be effective.

There is, of course, fairly empirical evidence he would not be as effective at United as he is at Dortmund, but nonetheless, having another go at getting Kagawa to work at Old Trafford would be a fun experiment.

Nani

Van Gaal has often spoken of United's need for speedy and creative wingers, per FourFourTwo, but there was one on the books when he arrived whom he allowed to leave. 

Admittedly, the idea of Van Gaal managing Nani seems farcical given how much the Dutchman prizes possession and how inconsistent the Portugal international could be with his decision-making. 

However, given United's desperate need for some creative spark, thoughts do occasionally turn to Nani, who certainly possessed the ability to pull off the unexpected. The odd screamer from outside the box would be a great asset to the Red Devils at the moment, and Nani managed a fair few of those at Old Trafford. 

This one, though, is not so much fantasy as a little wistful nostalgia. The reality of Nani was never quite as satisfying as his promise.

Danny Welbeck

The picture above is a tad difficult to look at for those United fans for whom Danny Welbeck was a true cult hero. 

He probably does not quite belong on this list because of his price tag—the £16 million Arsenal paid to acquire him could not really be called cheap.

He is in as an exception, though, because of his long connection with the club. His England team-mate Joe Hart said of Welbeck in an interview with Mark Bailey of the Evening Standard in 2013 that Welbeck was a "mad, mad, mad Manchester United fan."

He would also serve a useful function in this XI, dropping back to link midfield with attack, something United could have done with many times since he was sold to Arsenal in the summer of 2014. His goalscoring record will always be a knock against him, and many United fans were happy to see the back of him. For those of a more sentimental nature, though, it would nice to see him back at Old Trafford.

Carlos Tevez

Carlos Tevez is certainly not a beloved cult figure at United, but he was once. His decision to join Manchester City in 2009 once United failed to make his deal with the club permanent, and the way he embraced the rivalry from the other side, left a bitter aftertaste.

Even as he enters the latter stages of his career, though, he could still add energy and output to United on the pitch.

He is enjoying his time back in Argentina, where he has five goals in 12 Primera Division appearances for Boca Juniors. Imagining him running off Anthony Martial to create space is a nice thought, and in this XI, he could open up running lanes for the creative players behind him.

Javier Hernandez

Javier Hernandez was allowed to leave United for £7.3 million, a very reasonable price in today's market. He is certainly enjoying his time at Bayer Leverkusen, and he has scored more goals than any United striker this season—six in the league and four in the Champions League. 

His absence was keenly felt against Watford, when an attacking injury crisis meant United started with Memphis Depay and Jesse Lingard up front. Although Memphis managed to score in that game, the decision to sell Chicharito felt misguided as Van Gaal scrambled to find a striker.

Perhaps a bad fit for Van Gaal's side, Chicharito's absence is nonetheless felt as United struggle to find the net, something the Mexico international has a profound knack of doing.

All transfer values per Soccerbase. 

All advanced statistics per WhoScored.com.