Timlin, 42, has struggled to get in any kind of rhythm this season. In 24 outings, Timlin is 3-3 with a 7.06 ERA. Most recently, Timlin was pounded by the Phillies on June 16, giving up four hits and four runs over two-thirds of an inning.
"It's been something that, for the last whatever, it's been on the [injury] report for a while," said Red Sox manager Terry Francona. "It's been something he's been pitching through. I think it has something to do with some of the inconsistencies. He may not say that, because it's part of the reason he's good."
And true to form, Timlin declined an invitation to use the injury as the reason for his subpar performance.
"You know me, and you know how I'm going to answer that," Timlin said. "To me, that's an excuse. And I don't make excuses. I've just pitched badly. I can't blame it on anything else but my performance."
In recent years, Timlin has recovered from prolonged slumps. He hopes to do so again.
"At some point, why does a guy who's in the middle of a fight and getting his butt kicked get back up and win the fight?" Timlin said. "Because he's tired of getting beat all the time. You overcome the pain, you overcome whatever is going on and you do what you can."
It doesn't sound as if Timlin will go that long before getting back on his throwing program. Francona and pitching coach John Farrell spoke at length with Timlin about the move after Friday night's game.
"We're just trying to make sure we're doing the right thing," Francona said. "I think we all ended up agreeing this is probably the best thing for him and the organization. What we'd like to do is try to let this thing calm down in the next four or five days while we're home.
"We'll determine how his knee feels, how much he'll throw with John, and then let him go out to Triple-A and pitch a little bit -- once we all feel he's ready to do, where he can try to pitch effectively where he's able to get out over that front leg and not have to force. We'll see how that goes this week."
Timlin's first instinct was to keep pitching through the injury rather than shut it down. He was talked out of it.
"We talked," said Timlin. "They gave me some time to think about what I needed to do. Apparently, we agreed on it. It's been around a while. It's not something that's brand new. Every athlete plays with pain -- you just do. It's starting to get a little bit worse. We figured this would be a good time to take some time and let it cool down."
Manny Delcarmen and Craig Hansen have recently been serving as Francona's primary right-handed setup men, so the loss of Timlin shouldn't have a big impact on Boston's late-inning strategy.