Youkilis is not likely to play second, however. He will fill in at first and third, while Alex Cora will get the majority of playing time at second, for now. When Cora isn't slotted in at second base, Francona said Mueller would be the choice.
"I talked to Billy Mueller a little bit about going over there, maybe to give us a little flexibility," said the Boston manager. "He's willing to do that.
"There are some issues with him going over there that he worries about and I understand that. So we talked about that -- he's OK."
Mueller has been vocal about his apprehension for playing second, where he's started just five times this season.
"I just consider myself a third baseman and in an emergency situation, I'll go over there," said Miller. "I just don't have a lot of experience over there. In my own mind, I don't know if I'm helping the team over there, but in an emergency, I feel like I can fake it enough over there and try to do the job."
The 34-year-old has played just 53 games (including 43 starts) at second in his career, causing him to have concern that he can handle the position on a regular basis.
"Mainly my experience, turning a double play, and my experience around the bag," Mueller said. "Who knows what can happen around the bag. I think in that regard, you just have to try and do the best you can.
"Believe me, I'm here by all means, to help in any way I can and in any situation I can, and if I have to play whatever position, I will. They feel I can help the team at second, but sometimes, with my lack of experience [comes] a lack of confidence."
As for his decision not to pinch-hit for Alex Cora in the ninth against Mariano Rivera on Sunday -- a move that would have necessitated Mueller moving to second and Kevin Millar going to third -- Francona said he had made a promise to Mueller before the Sox infielder agreed Monday to the move.
"I had told Billy we would not do that," Francona said. "I don't think you can ever tell somebody something, and then the game gets on the line and then you say, 'I told you something but this inning is more important.' You can't do that. That's not right.
"There's always a time for conversations, and I thought Cora was going to get a hit."
Bellhorn begins healing: Bellhorn arrived in the Red Sox clubhouse Monday sporting a black splint to protect his left (glove) thumb, injured when he dove to make a stop of Jason Giambi grounder in right field Sunday night. "He was sore [Sunday] night and he's sore today," said Francona. "We kind of talked to him last night, but wanted to see how he showed up. I had spent some time talking to the doctor last night, and I don't think I was quite as optimistic after talking with doctors. But we wanted to wait for him to show up."
Not going prospecting: Francona and general manager Theo Epstein said they did not consider going to the minors and calling up either Dustin Pedroia or Hanley Ramirez, both younger middle infield prospects.
Pedroia is still healing from being hit on the wrist two weeks ago, shortly after being promoted to Triple-A Pawtucket.
"Pedroia got hit on the wrist pretty badly 10 days or two weeks ago and he's playing through it, but he's a little bit less than 100 percent. I think it's a little bit unfair for a kid like that to bring him up when he's less than 100 percent and 13 months out of college," Epstein said. "There are a lot of considerations there and we're excited about his future. We don't think he's too far away, but now is not the right time, considering he's playing his way back to 100 percent."
Ramirez began seeing action at second last week and gives the front office another middle infield option.
"Hanley's going to continue to play second base for the near future," Epstein said.
"He's had two games under his belt over there, and we'll see how he adjusts to that position, just to give us as many internal options as possible. And we're very excited about Hanley's future. At the same time, we want to balance the long-term development interests with the short-term needs of the big league club. We're playing a lot of teams in the next few weeks who put a lot of pressure on the defense in Tampa Bay, the White Sox, Tampa Bay again and the Twins, so you want someone over there who's pretty familiar with the position."
Foulke back in town: Keith Foulke returned to Fenway Monday to be examined by the Red Sox medical staff. The reliever had arthroscopic surgery on his left knee July 7, and spent the last several days in a strength program at the API facility in Arizona.
The Red Sox send Bronson Arroyo (7-5, 4.73 ERA) to the mound Tuesday against former Red Sox lefty Casey Fossum (4-7, 4.02 ERA). Arroyo will be facing Tampa Bay for the first time since April 24, when the two teams had two notable bench-clearing incidents following hit batsmen. The Sox right-hander earned the decision that day in Boston's 11-3 win.