Koji Uehara out as Red Sox closer

BOSTON -- A day after blowing his third consecutive save opportunity and taking his third loss in his last five appearances, the Boston Red Sox have temporarily removed Koji Uehara from the closer role.

Edward Mujica will take over ninth-inning duties.

Entering Thursday night's game against the New York Yankees with a 4-3 lead, Uehara gave up a game-tying home run to Mark Teixeira before surrendering a game-winning home run to Chase Headley two batters later. After the game, Uehara told Japanese reporters, "I'm responsible for everything, it's my fault," before quickly departing for the trainer's room and later offering a statement through team interpreter C.J. Matsumoto that "nothing was working."

Red Sox manager John Farrell had said Thursday night that he intended to speak with Uehara about the possibility of dialing things back, thus leading to Friday's decision.

"After having a chance to sit with Koji, he was understanding," Farrell said. "Understands the reason for it. We'll probably give him a couple of days to regroup some and then look to get him back in some lower-leverage situations before ideally we have him close out games before the season is out. That's the plan moving forward. When that is remains to be seen."

Farrell had also mentioned Thursday night the possibility of shutting Uehara down for the remainder of the season, an idea he backed away from Friday given the right-hander's apparent good health. As the team has done since signing Uehara as a free agent prior to the 2013 season, Farrell said the 39-year-old's workload will continue to be monitored carefully moving forward.

"There's no physical ailments, he doesn't complain of anything, he downplays the fatigue that has been discussed or written about or reported," Farrell said. "We have to factor all that in and yet not be blind to the number of appearances he's had over the last two years. There's no intent to shut him down, but yet we're dealing with a stretch of games that might be similar to one that he had back when he first started with [the Texas Rangers]. We're working with him to get through this."

The difference in Uehara's performance between last season and this season is significant. Opponents hit .097 against him after his installation as closer June 21, 2013, through the end of the season. They are hitting .221 this year. His ERA from June 21, 2013, to the end of year was 0.41, a comfortable lead over that time frame among relievers with 20 innings pitched. This season, it's 2.64.

Fatigue could definitely be a factor. He had not had a season with more than 70 innings pitched since 2008, his last season in Japan.

With Uehara, the Red Sox find themselves in an interesting predicament given the team's desire to see him regain momentum as a closer before entering 2015, despite his status as a free agent this offseason. However, Farrell maintained that Uehara's health is the team's main concern and will be for the rest of the season.

"He's earned the right to be dealt with the way he is," Farrell said. "We take the view of every player, regardless of their contract status, that their health is first and foremost. We're not going to do anything to jeopardize that.

"There's no denying his total body of work here. It's been elite. There's been a couple of stretches within that two years where, like any good pitcher, they're going to get challenged. When you look back over the course of his career in the states as a reliever, he's had these in the past. Just so happens it's happening at this time of the year. It doesn't deter our view and value of him by any means. That situation will take care of itself."

Since his last save on Aug. 12, Uehara's ERA on the season has risen from 1.29 to 2.64, the result of six outings in which he's been scored upon and given up 14 hits (four being home runs) in his last 4 2/3 innings pitched. Although the dip in production seems inexplicable, ESPN Stats & Info delved into the matter, pointing to Uehara's typically devastating split-fingered fastball as the source of his downfall this season.

Since June 16, the date in which he surrendered an extra-innings home run to Chris Parmelee of the Minnesota Twins, Uehara's splitter has accounted for 54 percent of his pitches compared with 42 percent prior. Along with the increase in usage, hitters' swing-and-miss percentages (44 percent to 37 percent) and strikeout percentages (45 percent to 23 percent) against the pitch have also dropped. Perhaps it's no coincidence that Uehara's ERA since June 17 is 4.85, a far cry from the 0.57 ERA he carried into that date.

Both home runs he surrendered Thursday night against the Yankees came on splitters.

"The first [spliiter] he threw [Teixeira], there was good depth to it, there was swing-and-miss," Farrell said. "And then after three consecutive ones, it didn't have the same consistent finish. That's where he's getting hurt right now is how many times does he throw it inside a given at-bat and does it have the same action to it."