Several hours before Game 1 at Tropicana Field on Friday, the Red Sox formalized their roster, and Timlin was the lone addition.
Coming off the roster was Minor League veteran Gil Velazquez, the middle infielder who was on the roster for the Game 4 finale of the Division Series when third baseman Mike Lowell had to be deactivated because of recurring right hip woes. Lowell is ineligible for the ALCS.
Telling Timlin, who has four World Series rings, that he was off the ALDS roster was a tough move for Francona. Putting him back on was far more appealing.
"I think we felt like in a potential seven-game series, we needed to have the extra pitcher," Francona said. "You get yourself into a little bit of a bind if you don't. It's certainly a lot more fun to give somebody good news than it is the other way. He's very deserving. He's been doing this a long time. I don't know how he will fit in or where he will pitch or when. We certainly don't know how the games are going to go beforehand, but I know there was a comfort level putting him on the roster."
Timlin went 4-4 this season with a 5.56 ERA. Lifetime in postseason play, he has a 3.94 ERA in 44 outings.
The Red Sox will stay with three catchers, as David Ross will again join Kevin Cash as backups to Jason Varitek.
Lowell was taken off the club's ALDS roster before Game 4 against the Angels because of a right hip injury. Per rules set by Major League Baseball last year, a player can be taken off of a roster in the middle of a series, but then loses his eligibility for the following round.
Cash will start Game 4, when veteran knuckleballer Tim Wakefield pitches. Ross will continue to be a late-inning replacement should the Red Sox opt to pinch-hit or pinch-run for Varitek or Cash.
With Lowell ineligible for this round, Francona said that Kevin Youkilis -- typically Boston's first baseman -- will be his primary third baseman. Youkilis came up through the Minor Leagues as a third baseman and started 32 games there this season and two more during the ALDS.
In Game 1, Francona will start Youkilis at third and Mark Kotsay, an outfielder by trade, at first.
The Red Sox have the ability to mix and match as the series evolves. Sean Casey might also see some time at first. Francona also has the option of keeping Youkilis at first, moving Jed Lowrie from shortstop to third base, and starting Alex Cora at shortstop.
"We'll probably mix and match a little bit -- Youk is probably going to play the majority at third," Francona said. "But things change when you don't know they're going to change. Youk will play third [in Game 1] and we'll go from there."
Here is the roster breakdown:
Pitchers (11): Jon Lester, Daisuke Matsuzaka, Josh Beckett, Wakefield, Paul Byrd, Jonathan Papelbon, Hideki Okajima, Manny Delcarmen, Justin Masterson, Javier Lopez and Timlin
Catchers (3): Varitek, Cash and Ross
Infielders (7): Youkilis, Dustin Pedroia, Lowrie, Cora; Casey, Kotsay and David Ortiz
Outfielders (4): Jason Bay, Jacoby Ellsbury, Drew and Coco Crisp
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.