"Naturally, a little bit," Lilly said when asked if he was concerned. "I'm trying not to let it, but it can drive you a little crazy. But guys deal with it all the time. I'm not the only one."
Lilly made a scoreless two-inning rehab appearance Sunday for Class A Rancho Cucamonga but was sore the next day and wasn't able to throw his routine between-starts bullpen session. Prior to that, it was hoped he'd rejoin the rotation by mid-August.
General manager Ned Colletti said the setback was a factor in Friday's acquisition of Joe Blanton from the Phillies.
Lilly needed arthroscopic shoulder cleanup in November 2009, so he knows the drill. He rebounded to make 30 starts in 2010, when he was acquired by the Dodgers from the Cubs at the Trade Deadline.
He has been determined to rehab and recover in time to help the club and put off any procedure until the offseason.
"There's a lot of excitement being in the middle of a pennant run," he said. "This is kind of what we play for, to play games down the stretch, and I want to find a way to keep myself involved. I'm trying to continue being positive."
Lilly, who was 5-1 with a 3.14 ERA when he went on the disabled list May 24, said he hadn't thought about moving to the bullpen. But if that's what it takes to be part of the Dodgers' stretch run, he said he'd be willing.
"I'd do whatever they want me to do," said Lilly, a career starter. "I wouldn't have a problem with that if it gave us the best chance to win the division. That's what the rest of the clubhouse wants, to win, and you can't be concerned with what one individual player wants."