BOSTON - Daisuke Matsuzaka will be on the mound for the Red Sox when the AL championship series begins Friday night against the Tampa Bay Rays.

That doesn't make him Boston's ace.

Josh Beckett is still No. 1 in the Red Sox rotation - especially during the playoffs - even though he had the worst outing of the three Boston starters who faced the Los Angeles Angels in the first round. Beckett, coming off a strained side muscle, is scheduled to pitch Game 2 in the best-of-seven series against the Rays.

“Before Beckett's last start, he was the best postseason pitcher maybe in the history of the game,” Red Sox manager Terry Francona said Wednesday after announcing his rotation. “He had the audacity to be a little rusty after two weeks. We don't need to run away from Beckett, we need to get him on a run.”

Francona chose Matsuzaka to start against the Rays in Game 1 not because of Beckett's injury, and certainly not because the team lost any faith in a guy who won five straight postseason outings before Boston's Game 3 loss to the Angels. Even with his off night versus L.A., Beckett is 6-2 with a 2.09 ERA in his postseason career.

Instead, Francona said, the Red Sox scheduled Beckett for the second game because it would give him, Matsuzaka and Game 3 starter Jon Lester