With the July 31 trade deadline looming in the not-too-distant future, contenders across Major League Baseball should already have their shopping lists drawn up.

We have our own notions of what should be atop each list.

We took a loose approach to defining what makes a contender, as not every team's status is determined by its record and/or standing in a given playoff race. Otherwise, this was about pinpointing where each team needs reinforcements the most.

We'll start with teams on the bubble and then move on to specific teams in the American League and National League postseason pictures.

On the Bubble

Arizona Diamondbacks: Starting Pitcher

In light of their 15-19 record since May 5, the Arizona Diamondbacks' current track veers more toward selling than buying. But if they opt to bolster their standing in the NL wild-card race, they'll need a starting pitcher to help carry their rotation while Luke Weaver recovers from a forearm injury.

Cleveland Indians: Offense

As Steve Adams covered at MLB Trade Rumors, the Cleveland Indians are in an extremely difficult position that could necessitate selling at the deadline. Yet the AL wild-card race isn't leaving them behind. If that remains the case, an offense that has struggled to score runs will need a bat or two.

Oakland Athletics: Starting Pitcher

Following their easy stroll to 97 wins in 2018, this season has been more of a step-forward, step-back experience for the Oakland Athletics. That could lead to a pragmatic approach to the trade deadline. But if they stick in the AL wild-card race, they'll need help for their motley-crew starting rotation.

New York Mets: Relief Pitcher

As the New York Mets stumble, executives around MLB might be eyeing deals for Zack Wheeler, Noah Syndergaard and Edwin Diaz. But since the Mets haven't yet stumbled their way out of the NL wild-card race, they ought to be eyeing upgrades for a bullpen that's put up a 5.03 ERA.

San Diego Padres: Starting Pitcher

The San Diego Padres have needed good luck to even get to .500, so they must be careful about sacrificing any of their prospect depth for the sake of saving their season. But if they must, they have the right idea (per Ken Rosenthal of Fox Sports) in coveting a No. 1 starting pitcher.

Tampa Bay Rays: Power Hitter

Record: 41-24, 1st in AL East

Although Craig Kimbrel ultimately signed with the Chicago Cubs, Rosenthal reported the Tampa Bay Rays were the runner-up for the seven-time All-Star closer.

If that seems odd, it's probably because the Rays are a notoriously frugal team. Additionally, their bullpen is already a functioning part of baseball's best run prevention machine.

The Rays should have some concern about their bullpen possibly burning out as the season goes along. Their relievers rank second in innings pitched, after all, and that isn't counting the innings that certain pitchers (e.g., Ryne Stanek, Yonny Chirinos and Ryan Yarbrough) have logged as openers.

However, Tampa Bay's greatest need is for more power in an offense that ranks ninth in the American League with 85 home runs. To this end, the right slugger would effectively complete a lineup that's already quietly one of the AL's best because of its impressive depth.

New York Yankees: Starting Pitcher

Record: 40-24, 2nd in AL East

The New York Yankees were in the running to sign 2015 AL Cy Young Award winner Dallas Keuchel, but they missed out when he signed with the Atlanta Braves on Friday.

At first glance, that might not have looked like a major loss for the Yankees. They're tied atop the AL East in part because their starting pitchers have posted the AL's fourth-best rotation ERA.

Look a little closer, however, and the cracks are obvious. 

Veteran left-handers James Paxton and CC Sabathia have spent time on the injured list, and breakout right-hander Domingo German just landed on the IL with a hip injury. Meanwhile, when and in what capacity Luis Severino will return from shoulder inflammation remain unknowns.

Hence why the Yankees aren't done seeking an impact starter. According to Ken Davidoff of the New York Post, they're even looking at San Francisco Giants lefty Madison Bumgarner and Toronto Blue Jays righty Marcus Stroman.

Boston Red Sox: Relief Pitcher

Record: 34-33, 3rd in AL East

It wasn't going to be easy for the Boston Red Sox to follow up last year's 108-win romp, but even they might not have anticipated this much hardship in 2019.

Injuries to veterans Mitch Moreland and Steve Pearce and rookie Michael Chavis' slump have first base currently looking like a problem area. The Red Sox are also a man short in their rotation, and hard-throwing righty Nathan Eovaldi recently hit a setback in his recovery from elbow surgery.

But whereas the Red Sox can be patient and hope these matters resolve themselves, they'll need to address their bullpen more urgently.

Red Sox relievers have arguably been better than expected this season, but things get dicey outside of righties Matt Barnes, Brandon Workman, Marcus Walden and Heath Hembree. In particular, fellow righty Ryan Brasier has been a disappointment following his breakout 2018 season.

Minnesota Twins: Relief Pitcher

Record: 43-21, 1st in AL Central

The Minnesota Twins don't need to worry about holding on to the AL Central lead.

The Cleveland Indians aren't pushing them for it, after all, and it isn't as though the Twins are overachieving. Courtesy mainly of their explosive offense, they've scored 112 more runs than they've allowed.

All the Twins need to worry about at this point is getting ready for the postseason. To this end, they could use an extra arm in both their rotation and their bullpen.

Between the two, their pen should take priority. It's been stumbling with a 5.18 ERA over the last 30 days. Righty closer Blake Parker deserves a chunk of the blame for that, as he's allowed seven earned runs in his last five appearances.

If the Twins can find a righty reliever who can match or even exceed the strikeout dominance of lefty Taylor Rogers, that would be ideal.

Houston Astros: First Base and/or Designated Hitter

Record: 45-22, 1st in AL West

After winning 101 games in 2017 and 103 games in 2018, the Houston Astros now find themselves on pace for a staggering 109 wins this season.

However, things haven't been so smooth as of late. The Astros have had to put stars George Springer (hamstring), Carlos Correa (rib) and Jose Altuve (hamstring) on the injured list, and their once-mighty offense has struggled accordingly.

Under these circumstances, it's hard to ignore that Yuli Gurriel and Tyler White have combined for only a .645 OPS as Houston's primary first baseman and designated hitter, respectively. Either or both spots would benefit from a veteran upgrade.

Otherwise, the Astros could seek a reliable No. 5 starter or an extra arm for their bullpen. But come October, neither would potentially benefit them as much as making their offense—which had previously been on track for historic excellence—into a truly overpowering force.

Texas Rangers: Catcher

Record: 35-30, 2nd in AL West

The Texas Rangers weren't supposed to contend this season after they lost 95 games in 2018. Yet it's happening, largely because only the Twins have outscored them.

Preventing runs has been the hard part for the Rangers. Their starters, in particular, have a 4.93 ERA despite excellent work by veterans Mike Minor and Lance Lynn.

While the Rangers could seek impact starters, they aren't in a position to pay exorbitant prices for the best players on the trade market. They're better off seeking opportunistic deals. And if they go that route, they should focus on making their offense even better.

No position needs an upgrade as much as catcher, as Jeff Mathis and Isiah Kiner-Falefa have thus far produced only a .562 OPS. It's looking like a buyer's market for catchers, so the Rangers might find a substantial fix for their problem at an unsubstantial cost.

Philadelphia Phillies: Outfielder

Record: 37-29, T-1st in NL East

The Philadelphia Phillies are barely holding on to first place in the NL East as is, and they now have a skeleton crew in their outfield.

Bryce Harper is still standing, but fellow former MVP Andrew McCutchen is out for the year with a torn ACL. Odubel Herrera is likely facing a suspension following his arrest after allegedly assaulting his girlfriend. And on Saturday, rookie Adam Haseley hit the IL with a groin strain.

According to Jon Paul Morosi of MLB.com, the Phillies were said to be "in on everything" following McCutchen's injury. That "everything" supposedly includes more than just outfielders, but there's little question that's the club's biggest need.

While they're at it, the Phillies should also keep their eyes peeled for starters and relievers. Their rotation and bullpen have functioned reasonably well to this point, but both would benefit from a new arm or two.

Atlanta Braves: Relief Pitcher

Record: 37-29, T-1st in NL East

Now that the Atlanta Braves have Dallas Keuchel, their starting rotation should be set.

Prior to Keuchel's arrival, Atlanta's rotation had been a problem. Its 4.26 ERA isn't terrible, but that obscures some less-than-stellar peripherals and disappointing seasons from Kevin Gausman and Mike Foltynewicz. Having Keuchel alongside Max Fried, Julio Teheran and Mike Soroka should lead to greater stability.

The Braves now need to bolster their bullpen.

It also has a 4.26 ERA, and it's struggled with both walks and home runs. Atlanta needs at least one more shutdown arm next to Luke Jackson, Sean Newcomb and Jacob Webb.

Said shutdown arm might have been Craig Kimbrel, but it seems like the Braves never seriously pursued a reunion with him. Luckily, there are plenty of Kimbrel alternatives on the trade market, and they have the prospect depth to acquire whichever one they like.

Milwaukee Brewers: Starting Pitcher

Record: 38-28, 1st in NL Central

At various points this season, the Milwaukee Brewers have needed additional offense around reigning NL MVP Christian Yelich and relievers to help out nuclear lefty Josh Hader.

They've also needed better starting pitching.

To their credit, the Brewers have been able to hide that need well enough. Zach Davies and Brandon Woodruff have pitched well from the beginning, and Gio Gonzalez provided a shot in the arm when he rejoined the Brewers in late April. More recently, Jimmy Nelson returned from a long absence.

Milwaukee's rotation nonetheless has a 4.58 ERA, and it's reeling from injuries to Gonzalez (arm) and Jhoulys Chacin (back). Additionally, Nelson's return was a three-inning dud.

The Brewers could have used Dallas Keuchel as a stabilizer for their rotation. But now that he's off the market, their standing in the NL Central gives them little choice but to focus on standouts such as Madison Bumgarner and Marcus Stroman as potential saviors.

Chicago Cubs: Another Relief Pitcher

Record: 37-28, 2nd in NL Central

The Chicago Cubs filled an obvious need when they signed Craig Kimbrel.

The Cubs went into the 2018-19 offseason with major holes in their bullpen, yet they only went so far as to pursue minor upgrades. That bit them early this season, as their pen was littered with red flags before Kimbrel came aboard last week.

Still, the Cubs shouldn't stop tinkering with their pen. Kyle Ryan isn't excelling at his role as a lefty specialist, and the team has to hold its breath whenever righties Brad Brach or Carl Edwards Jr. are toeing the slab. The Cubs can do better than these guys.

They otherwise have plenty for the stretch run. Their offense has been inconsistent—which is actually putting it kindly for their second basemen—but it has talent in abundance. Their rotation, meanwhile, is about as good as its 3.67 ERA would imply.

St. Louis Cardinals: Starting Pitcher

Record: 32-32, 3rd in NL Central

The St. Louis Cardinals are 12-22 dating back to May 2. During this time, they've gone from a 2.5-game lead to a 5.0-game deficit in the NL Central.

But while these are the trappings of a trade-season seller, the Cardinals are very much a win-now team. And even if they wanted to sell, they'd probably only go as far as putting their pending free agents on the market. Slugging outfielder Marcell Ozuna is the only one with any real value.

As far as what the Cardinals should buy if they go that route, the sorry state of their starting rotation is one of the worst-kept secrets in baseball.

Cardinals starters should be flattered by their 4.35 ERA, as only young righty Dakota Hudson has been even a shade of reliable this season. Notably, young-ish righty Michael Wacha was recently demoted to the bullpen, and veteran righty Adam Wainwright hurt his hamstring Sunday.

The Cardinals should think twice about shopping for rental starters, but no potential upgrades should be totally off-limits for them.

Los Angeles Dodgers: Relief Pitcher

Record: 45-22, 1st in NL West

The Los Angeles Dodgers have the best record in the National League, as well as a plus-107 run differential that confirms they more or less deserve it.

Just imagine if they had even a halfway-decent bullpen.

There are worse ERAs than the 4.56 mark that Dodgers relievers have compiled so far, but theirs comes with a notable shortage of strikeouts and a damning effect on the club's win probability.

The bright side is that the Dodgers are safe when the ball is in the hands of Kenley Jansen or Pedro Baez. The former got off to a rough start this year, but he's been dominant in his last nine times out.

Even still, the Dodgers need better righties than Joe Kelly and Yimi Garcia, and potentially a better lefty specialist than Scott Alexander. Per Jansen's request (via Dylan Hernandez of the Los Angeles Times), the only thing the Dodgers shouldn't be looking for is a new closer.

Colorado Rockies: Offense

Record: 34-31, T-2nd in NL West

The Colorado Rockies might not seem like a major player in the NL playoff picture. But they're 31-19 dating back to April 14, and they aren't in a position to sell even if they wanted to.

As always, the Rockies could use more pitching. That's especially true in the wake of Kyle Freeland's demotion to the minor leagues. With that, a void opened up in Colorado's rotation after hard-throwing righties German Marquez and Jon Gray.

It isn't all bad, though. Peter Lambert established himself as a keeper in his masterful debut Thursday. And considering he was a Cy Young Award contender last season, all may not be lost for Freeland just yet.

A more overarching concern is the Rockies offense. It wasn't good in 2018, and it's on track to be just as bad (if not worse) in 2019. The Rockies simply need more good hitters around Nolan Arenado, Trevor Story and Charlie Blackmon, but second base would be the best place to put one.

Stats courtesy of Baseball Reference and FanGraphs.