The Red Sox's struggles this year have been blamed on any number of deficiencies up and down the club's roster. Before the season even opened, the starting staff was already under the microscope, and that scrutiny only intensified when the rotation got off to a horrid start, which ultimately cost Juan Nieves his job. Yet just as the pitching staff began showing signs of improvement, Boston's offensive production took a nosedive in the month of May.

For over a month, the Red Sox had one of baseball's worst offenses, and their run production was a far cry from preseason expectations.

Over the past couple weeks, however, Boston's bats and starting pitching have begun to round into form. The Red Sox are scoring runs like they are supposed to, and the arrival of Eduardo Rodriguez, along with Clay Buchholz's All-Star level performance and Wade Miley's 3.70 ERA since May, has given the rotation at least a semblance of stability. As a result, the Red Sox are beginning to play like the team general manager Ben Cherington probably expected them to be this offseason.

Still, one area of Boston's roster remains worrisome, even if it hasn't gotten the same level of scrutiny as the offense or rotation. The Red Sox bullpen is teetering on the edge of failure despite the club's recent run of success. A lack of bullpen depth is threatening to derail the squad's hopes of climbing back into contention even as the rest of the roster is performing adequately.

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Heading into Wednesday, Boston's bullpen has the sixth-highest ERA in all of baseball at 3.98. By some measure, they've been even worse than that. Red Sox relievers have the second-worst FIP in MLB at 4.34, ahead of only the Rangers. When the starters exit the game, the team's relievers don't pick up many strikeouts, and they don't do a good job of keeping the ball in the yard either.

In fact, the Red Sox bullpen has the worst HR/9 rate in the majors this season. Only Tampa Bay's relievers have given up more home runs than Boston's, and that's largely because the Rays depend on their bullpen more than any other team in the game.

Outside of Koji Uehara and Junichi Tazawa, the Red Sox have no relievers with a consistent track record and recent run of success in the big leagues. That's led Boston to lean heavily on the two right-handers, especially Tazawa, who the team avoided using for a full week until Sunday's win likely because he had been overworked.

Tazawa's brief absence, which was felt most notably in last Friday's extra-innings loss to Houston, underscored how few reliable relievers the Red Sox have to turn to in key situations. Alexi Ogando, who leads the team's bullpen in innings pitched (38), exemplifies just what is plaguing Boston's pitching staff in the latter parts of the game. Ogando doesn't strike opponents out, and he's susceptible to the long ball, having given up more home runs this year (seven) than Buchholz (five) in roughly one-third the number of innings.

The club's thin depth in the bullpen has forced John Farrell to rely on the likes of Tommy Layne and Robbie Ross more than he should. Both can succeed in the right role (namely, against left-handed hitters), but neither is dependable under a heavy workload or in high-leverage situations.

Cherington has tried to find solutions internally throughout the season. Matt Barnes, Jonathan Aro, Heath Hembree, Dalier Hinojosa, and most recently Noe Ramirez have all been called up from Pawtucket and given opportunities to make an impact. But none have provided any type of solution to Boston's bullpen issues.

Whether the Red Sox look to acquire relief help via trade is the next question. On Monday, Peter Gammons wrote that the club could be looking at Braves righty Jason Grilli as a possible addition. The A's are also likely to deal closer Tyler Clippard in the coming weeks, and he'd certainly represent an upgrade as well.

Of course, Jonathan Papelbon has been itching for a trade from the Phillies for a couple years now, though one shouldn't expect a reunion with the Red Sox. Papelbon's been good each of the past two seasons, but Philadelphia's never been an easy trade partner, and Cherington is probably better off seeking a cheaper alternative. Plus, Papelbon won't waive his no-trade clause if he isn't closing, and while the Sox need another impact reliever, it's unclear if they would be willing to move Uehara out of that role for Paps.

Just what kind of help the Red Sox can land remains uncertain, but there's little denying the team's shaky bullpen is threatening to spoil any chance for contention in the second half. Pat Light is an intriguing option down in Pawtucket, yet he has just nine appearances in Triple-A under his belt. He needs some more seasoning despite his electric fastball.

There aren't any easy solutions here for the Red Sox. That Boston's relievers are struggling so much makes Cherington's job even more difficult as the trade deadline approaches. Beyond determining just how much of a shot this team has at catching its division rivals, Cherington has to figure out where to make upgrades on the roster.

The calls for Cole Hamels will surely continue, but the Red Sox rotation has been less of a problem lately. Upgrading Boston's bullpen is the most important task facing Cherington and the club's front office in the coming weeks.