After the 2010 season, the Red Sox  recognized that they needed to upgrade their bullpen. The team considered right-hander Koji Uehara, who had put up some eye-popping numbers out of Baltimore’s bullpen that year, but the team steered clear of the bidding for his services because of what it viewed as too many medical red flags for a pitcher who would be 36 the following season. And so, Uehara returned to the Orioles on a one-year, $3 million deal (with a $4 million club option), while the Sox signed right-hander Bobby Jenks  to a two-year, $12 million deal.
Jenks’ history in Boston proved brief and disastrous. Uehara, meanwhile, proved one of the most dominant relievers in the American League . Though he missed about two and a half months in 2012 with a strained lat, he finished strong, with scoreless appearances in 16 of his 17 contests after returning from the DL in mid-August. That punctuated a stretch in which he offered enormous return on the deal to which the O’s signed him.
Uehara logged a total of 101 innings with a 2.14 ERA over the last two years, with 128 strikeouts and just 12 walks in 101 innings. His excellence made him a critical trade chip for Baltimore, which dealt the right-hander to the Rangers in the middle of 2011 (when he had one and a half years of team control remaining) for Chris Davis  and Tommy Hunter . (Davis smashed 33 homers for the O’s in 2012, while Hunter provided the O’s with some depth in both their rotation and bullpen.
Clearly, he represented a missed opportunity for the Sox the last time he was a free agent. The team didn’t want to pass on another opportunity to acquire him, particularly given that he was available on just a one-year deal. There were three pitchers in the big leagues who had a strikeout-to-walk rate of 9-to-1 or better in 2012. The Sox now have two of them in Uehara and Junichi Tazawa. While the Sox didn’t have a profound bullpen need, Uehara’s track record suggests that he is a pitcher for whom it is worth reshuffling the deck.
A few additional thoughts on the Red Sox’ deal with Uehara, whom a major league source confirmed had agreed (pending a physical) to a one-year deal with Boston. The agreement (first reported by the Dallas Morning News) is reportedly for $4.25 million.
- Since 1901, 14 major league pitchers have logged at least 100 career innings with a strikeout-to-walk rate of better than 4-to-1. Not only is Uehara in that elite mix — he’s pulled away from it in a fashion that has turned him into a distant speck on the horizon. In parts of four big league seasons, Uehara has a 7.97 strikeout-to-walk ratio, having punched out 239 batters and walked just 29. Only Sergio Romo (5.77 K-to-BB) joins him in the list of pitchers with a rate of better than 5-to-1.
- Last year, Uehara struck out 43 and walked just three, a 14.33 strikeout-to-walk rate. Only Hall of Famer Dennis Eckersley has ever topped that ratio in a season that featured 30 innings of work. (Impressively, Eckersley did it twice, having exceeded an 18-to-1 strikeout to walk rate in BOTH 1989 and 1990.)
- He’s American League East battle-tested, having recorded a 3.03 ERA and 6.6 strikeout-to-walk rate for the Orioles from 2009 until being traded halfway through 2011. That includes his time as a starter in 2009 and a reliever in 2010-11. He was spectacular out of the bullpen, however, with a 2.27 ERA, a 9-to-1 strikeout-to-walk rate, 11.6 strikeouts per nine innings and 1.29 walks per nine.
In short, Uehara’s track record is remarkable, someone who — if (big if) healthy — can be one of the better right-handed relievers in the game, capable of dominating hitters from both side of the plate. But what does his arrival mean for the rest of the Sox bullpen?
Here’s a look at how things line up for the rest of the bullpen:
RHP Andrew Bailey  (three options)
RHP Mark Melancon  (out of options)
RHP Alfredo Aceves  (one option)
RHP Daniel Bard  (two options)
RHP Chris Carpenter  (two options)
RHP Junichi Tazawa (one option)
RHP Clayton Mortensen (out of options)
RHP Pedro Beato (two options)
RHP Alex Wilson (three options)
LHP Craig Breslow  (out of options)
LHP Franklin Morales  (out of options)
LHP Andrew Miller  (out of options)
That’s 12 options for what will likely be seven spots. There’s a good chance Beato will be peeled off the 40-man roster to make room for Uehara, who in combination with the additions of Mike Napoli  and Shane Victorino , will push the Sox one over the 40-man roster limit. Wilson and Carpenter likely will be sent down as primary depth options.
Still, the Sox must clear an additional two spots from the bullpen. Perhaps Aceves will be dealt. Mortensen, who impressed throughout 2012, could be on the bubble. And right there with him?
After the right-hander’s dreadful 2012 season, nothing can be taken for granted as he prepares for the coming season. If he is still searching throughout spring training, then given the fact that the team would want him to get consistent work and the fact that he has options, the best solution might be for him to start the year back in Triple-A, until he proves he can dominate again.
Of course, that might come in spring training. But it’s an outcome that the Sox can’t take for granted, something that the team may be acknowledging quietly with the acquisition of Uehara.