BOSTON -- Matt Barnes had been grinding it out with discomfort in his left hip for at least 10 days, but the Red Sox decided that was no longer a smart move.
The righty setup man, who last pitched on Monday in Atlanta, will be shut down for at least the next several days.
An MRI on Thursday detected inflammation for Barnes, who had a 3.39 ERA and has held opponents to a .190 average in 58 appearances this season.
"I'm in the process of working with the medical staff and doing treatment and trying to get back as soon as possible," said Barnes. "There's the discomfort of pitching with it a little bit. The biggest thing is you kind of subconsciously compensate. We don't want to do that. We want to make sure I'm completely healthy. We felt like this was the right time to do it."

With the Red Sox holding an 8 1/2-game lead in the American League East entering Saturday with 20 games left in the regular season, it is vital that the team has as many healthy relievers as possible.
"We're at the point where we don't want to hurt it anymore," said Barnes. "I don't think that's fair to the team to go out there and to be pitching at anything less myself or the team thinks I'm capable of. This team anticipates playing and expects to play all the way until the World Series, and I think right now our focus is on making sure I'm healthy enough where I can go out there and pitch three days in a row in October."

When will Barnes resume throwing?
"When we feel that the symptoms are not there, then we'll decide what's next," said manager Alex Cora. "Hopefully, like I said yesterday, sooner rather than later, and he can go out there and start doing his flat-ground [work] and throwing bullpen [sessions], and we'll see where he goes."
With Barnes temporarily out of the mix, it could open up an opportunity for some of the other relievers to showcase their stuff in high-leverage situations.
Joe Kelly, Tyler Thornburg, Richard Hembree and Brandon Workman are among the pitchers who will likely be called on more often while Barnes is out.
Phillips could play first by Sunday
Cora first mentioned on Friday that the club is having Brandon Phillips do early work at first base, a position he has never played. The team is confident enough in the veteran's athleticism that he could start there as soon as Sunday night, when the Red Sox face lefty Dallas Keuchel.

"As soon as he gets his first-base mitt," quipped Cora. "He took ground balls yesterday, and he's doing good. Obviously, it's a lot different. We went through this in '08 with [Mark] Kotsay. Not too many people felt that he was going to be able to play first base, and then he was playing first base in Game 7 of the ALCS. So it's a lot of repetition. He has good instincts. It's not as easy as people think."
Catch-22
The Red Sox are in the rare position of not really knowing who their primary catcher is with three weeks to go in the regular season. Christian Vazquez was the guy earlier this year, and Sandy Leon handled the bulk of the load while Vazquez was out. But now both are on a roster that also includes Blake Swihart. Vazquez got the nod on Saturday, but Cora will go with Swihart on Sunday, meaning all three catchers will have started one game in this series.

The pitchers -- particularly Chris Sale and Rick Porcello -- have been most comfortable working with Leon. But Leon has slumped mightily at the plate of late, going hitless in his past 19 at-bats and getting just three hits in his past 40 at-bats.
"The three of them are really, really good," said Cora. "They bring different skill sets. They've been good for us. Early in the season, it was very hard for me to play three of them, but then Blake played and did really good. We can see what he can do defensively, although we have no doubts that he can call the game and all that stuff. It's like, yeah, everything we thought is there and offensively, he can do a lot of things. Right now, I'm good where we're at. We'll see where we go in the next few weeks."