MLB Trade Deadline: 5 GMs Under the Most Pressure to Pull off a Blockbuster

It's May, and there are surprises and disappointments across baseball. 

The Red Sox, among other teams, are on the disappointment end of the spectrum. Their recent history and high payroll should suggest a team that is in contention for the playoffs, but in fact they are in last place in the AL East.

Find out which five GM's are under the most pressure this spring and summer to pull off a blockbuster deal.

Ben Cherington, Red Sox

Ben Cherington is in his first year as Red Sox GM, but he has to be feeling the pressure right now to acquire a top-line starting pitcher. 

The Red Sox are 28th in MLB in ERA, allowing 4.76 runs per nine innings. Boston is in last place in the competitive AL East, and the fanbase has not forgotten the epic collapse last September. 

The Red Sox's pitching cost them during last year's choke, and it still is the team's Achilles' heel.

Clay Bucholz isn't the pitcher everyone thought he was, and Jon Lester is the only starter with a sub-four ERA. 

The Red Sox need to improve their starting pitching.

Brian R. Sabean, Giants

Once again, the San Francisco Giants offense is near the bottom of the league. The Giants are 25th in MLB in runs scored despite having the 10th best batting average at .257. 

Right now Brandon Belt is a disaster at first base with a .239 average and zero homers. Aubrey Huff is hitting below the Mendoza line. First base is a market with a plethora of readily available talent. 

The Giants missed the postseason in 2011 after winning the World Series in the prior season. Last year's blockbuster trade to acquire Carlos Beltran didn't quite work out. 

Sabean is under pressure to fix the team's offensive woes and get the team into the playoffs. 

Doug Melvin, Brewers

After losing Prince Fielder to free agency, many thought the Brewers would fall off the map. At 16-20 right now, they have. 

This team can still make the playoffs, but GM Doug Melvin has to make a move or two due to the amount of injuries the Brewers have incurred.

Carlos Gomez resides on the 15-day disabled list, shortstop Alex Gonzalez will miss the rest of the season with an ACL tear, Mat Gamel is out and pitcher Chris Narveson is on the 60-day DL.

In addition to the injury problems, Aramis Ramirez hasn't panned out so far, and Rickie Weeks is in a horrid slump. 

After making the NLCS last year, Melvin has a lot of pressure on his shoulders to return to the playoffs. With the injury report looking dim, Melvin needs to do so via trade. 

Jerry DiPoto, Angels

Despite having the fourth-highest payroll in MLB, the Angels are in third place in the AL West. 

DiPoto signed Albert Pujols for a 10-year, $240 million contract that looks worse and worse by the day. 

It's the middle of May, and Pujols is hitting .212 with one homer. This Angels team was supposed to be contenders with Pujols in the lineup but look no better than before. 

On paper the Angels have a solid team, but for some reason the Angels haven't performed thus far. The weight falls on DiPoto to improve this team.

Ruben Amaro Jr., Phillies

The Philadelphia Phillies have won the NL East for the past five years and have the second-highest payroll in MLB.

Ryan Howard and Chase Utley continue to nurse various injuries, and their loss is hurting the Phillies significantly. 

Last year Amaro Jr. made a brilliant blockbuster trade in acquiring outfielder Hunter Pence. 

Amaro has a good history, headlined by trading Cliff Lee for Roy Halladay and then getting Lee back shortly later. 

The Phillies can't stand to remain in last place in the NL East, and Amaro needs to pull off another blockbuster for that to happen.