Lester was scheduled to replace Julian Tavarez for tomorrow's game at Cleveland, the 23-year-old left-hander's first major league appearance since he beat the Los Angeles Angels on Aug. 23 last year. The Red Sox said nine days later that he had a treatable form of lymphoma.

"I don't think it really has sunken in yet, and I don't think it will sink in until tomorrow when I get on the mound," Lester said Sunday.

Lester was 7-2 with a 4.76 ERA and 60 strikeouts in 81 1-3 innings last year after being recalled from Triple-A Pawtucket of the International League in June.

"It's definitely a lot more gratifying than
he Red Sox during spring training and started the season on the disabled list. He was activated on June 11, but immediately was optioned to the minors.

"It's been hard, but you have to sit back and see that they have your best interest involved," Lester said. "It's been hard getting treated like you're in a glass bottle, so it'd be nice to finally break through and get to pitch again."

Lester went 4-5 with a 3.61 ERA with Class A Greenville of the South-Atlantic League and Pawtucket, winning three of his last four decisions. Lester was 4-5 with a 3.89 ERA in 14 starts with the PawSox and had a 2.08 ERA in three starts and Greenville.

"I can't sit here and tell you there won't be some emotion involved," Red Sox manager Terry Francona said. "I think his folks are going to be there, which I'm sure for them will be extra special."

Francona said the decision to recall Lester made sense from a baseball perspective and wasn't influenced by emotion.

"We didn't let it be, or he would have been here three months ago," Francona said. "I wouldn't apologize to be crazy about a kid like Lester — I'd be crazy not to. But I wouldn't ever let that get in the way of making decisions."

Francona said there will be no pitch counts or limitations on Lester, who allowed three runs and seven hits in seven innings against Ottawa on Wednesday.

Tavarez, 5-8 with a 5.27 ERA in 18 starts, will be switched to a reliever.