Because they had so many off-days in the ALDS, the Sox went with three catchers and just 10 pitchers, leaving Timlin as the odd man out.
For the 42-year-old righty, a part of four World Series championship teams, it was a tough pill to swallow. But Timlin took it with class.
"It was frustrating at the beginning," said Timlin, who posted a 5.66 ERA in 47 appearances this season. "I've got to accept my role and I have to help the team when I can. Think positive. It's not going to do any good to be moping on the bench. Be positive, go get 'em, help the guys out."
Red Sox manager Terry Francona said that the team hasn't decided on a 25-man roster yet, but will likely do so before taking the field in St. Petersburg for Thursday's workout. Game 1 is on Friday night at Tropicana Field.
"We have a lot of meetings tomorrow in [St. Petersburg]," Francona said. "We have a workout at 3 p.m. and we'll have our meetings in the morning. I think we'll have a meeting from 9 a.m. to 1:30 p.m., we'll work out at 3 p.m. and I think we'll probably have our roster to announce tomorrow before the workout."
David Ross, the third catcher, would come off the roster if Timlin is added. Timlin has 44 postseason appearances under his belt, posting a 3.94 ERA.
Third baseman Mike Lowell (partial tear of the labrum in his right hip) is ineligible this round after being taken off the ALDS roster prior to Game 4.
Minor League veteran Gil Velazquez (four days of Major League service time) is likely to hold down that roster spot. Julio Lugo, who hasn't played since July 11 after tearing his left quad, continues to work out. However, Francona said it's unlikely Lugo is in strong enough shape physically to be activated for this round.
"I think it's been too long," said Francona. "I give him a lot of credit. He's trying. I do want to have a conversation with him, but I don't know how realistic it is to ask somebody to do that right now. We'll go out and have a conversation with him."
As for how the starting lineup shakes out in Lowell's absence, Francona said there are still some more discussions to take place. Will he go with a set lineup of Kevin Youkilis at third base and Mark Kotsay or Sean Casey playing first? Or will he mix and match and at times, keep Youkilis at first, with Jed Lowrie moving to third and Alex Cora playing short?
"That's a good question and I don't have that answer yet," said Francona. "I need to look at some of our stuff and sit through our meetings, and I'll hopefully have a much better idea how we want to do it. I need to look at that a little bit more in depth."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.