The Boston Red Sox have had a very disappointing 2014 season.

Their offense, projected to be one of baseball’s best before the year began, ranks just 26th in the majors in runs scored with 354. Their rotation, which boasts veteran depth and promising rookie contributors, ranks at just 23rd in baseball, with a collective ERA of 4.11. And the Red Sox’s fielding—so good a year ago—has been noticeably poorer this year, as is evidenced by the 56 errors Boston has committed so far.

Yet amid all of the poor performances that have led to Boston’s 42-51 record, the back end of the bullpen has been phenomenal. All-Star closer Koji Uehara has been a huge part of that, of course, and has further solidified his reputation as one of the best relievers in baseball.

But left-handed setup man Andrew Miller is having just as impressive a year, and it’s Miller who could serve as the Red Sox’s closer of the future.

When you think of where Miller was just a few seasons ago, his transformation is fairly remarkable.

When the Red Sox acquired Miller before the 2011 season, they took him on as a major reclamation project and as a starting pitcher. Miller has always had phenomenal stuff, but a lack of command plagued him throughout his career as a starter.

After posting a 5.54 ERA for the Red Sox in 2011—a year in which he made 12 starts—Miller transitioned into a reliever role, where he’s been ever since.

Miller was good in relief in 2012 and 2013, striking out a ton of batters and posting a solid ERA, but he was still walking around five batters per nine innings. That prevented him from truly reaching the upper echelon of elite relievers in the game despite some eye-popping strikeout numbers (99 in 71 innings).

This year, however, Miller has dropped his walk rate to a career-low 2.78, and the effect that’s had on his stat line is dramatic. Take a look at how Miller stacks up to the average reliever this year:

Those numbers are why FanGraphs has Miller as the 10th-most valuable reliever in the game this year, tied with Pat Neshek, Uehara and Steve Cishek with a 1.3 fWAR and less than half a win behind FanGraphs‘ third-best reliever, Aroldis Chapman. Uehara earned the All-Star nod because he’s the closer, but Miller deserves to be there, too.

Unfortunately for the Red Sox, both Uehara and Miller are free agents after the season. While you have to assume Boston would like to bring both back, one or both could be traded at the deadline this season, and retaining the services of both could prove quite expensive.

Yet as crazy as it sounds, while Miller and Uehara have been equally efficient this season, and while Uehara has been better for longer and on a brighter stage, there’s reason to prefer Miller moving forward.

Perhaps most obviously, Miller is just 29, while Uehara is 39 and generally not able to pitch back-to-back games. Uehara has a history of shoulder trouble, while Miller’s injuries generally haven’t been related to his arm. And while Miller walks more batters than Uehara, he also strikes out more batters and induces more ground balls.

It’s fair to argue that we don’t know that Miller will be able to hold down the ninth inning with regularity, but we also don’t know that he can’t. And while there’s some additional mental pressure that comes with closing out games, it’s not like Miller isn’t used to pitching in high-leverage situations with the game on the line regularly.

Bringing back Uehara and Miller for another run in 2015 is something the Red Sox would be wise to consider, but if they can truly only retain one, it would be perfectly reasonable for them to choose Miller over their standout closer. At best, Uehara probably has one or two seasons remaining, while Miller could pitch for the better part of the next decade.

While major contracts for relievers are rarely a good idea, a three-year contract for Miller could make sense for both sides. Miller hinted to Brian MacPherson of The Providence Journal that he’d like to return to Boston, but the two sides haven’t discussed a deal so far.

Perhaps Miller prefers to close and will seek that opportunity elsewhere. He’s certainly earned it with his performance over the past three years.

But the odds are decent that Miller will get that chance in Boston in fairly short order, too. And if Miller is to serve as the Red Sox closer in the future, the Red Sox will be in good hands.

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