BOSTON -- When it comes to injuries or health issues, Red Sox pitcher Jon Lester would rather not comment.

Boston’s left-handed ace was placed on the 15-day disabled list Wednesday with a lower left lat strain and has been shut down from throwing until at least after the upcoming All-Star break. When approached Thursday to discuss his injury and trip to the DL, Lester took a pass.

“I’m not about to give daily updates,” he said. “It is what it is. We’ll treat it and move on. I’m not concerned. It’s nothing serious.”

Lester is all about moving on.

This is his first time on the DL since being diagnosed with anaplastic large cell lymphoma in August of 2006. During his recovery he had difficulties dealing with his public battle with cancer, only because, as he’ll admit now, he didn’t know how to handle dealing with the disease on a personal level.

So, when it comes to a lat strain, it’s no big deal to Lester.

That’s not to say there’s no reason for concern. He was, after all, removed from Tuesday’s game after four no-hit innings. His injury has typically sidelined pitchers from 2-4 weeks, but there have been cases that have resulted in long-term absences. An MRI on Wednesday confirmed the lat strain diagnosis.

Team physician Thomas Gill released a statement Wednesday night: “He will be treated with a period of rest from throwing, followed by progressive strengthening program. There is no specific timeframe for his return at this time. His status will be better defined following the All-Star break.”

Lester, 10-4 with a 3.31 ERA this season, was in the clubhouse Thursday afternoon and went through his normal daily routine. He went out with his fellow pitchers for their stretch and watched as they participated in running drills.

The Red Sox are hopeful he will be ready to return shortly after he is eligible to come off the DL (July 22), but if he’s not, the team could find itself in a pickle. With Daisuke Matsuzaka out for the season, Clay Buchholz out with a back injury, John Lackey struggling with consistency and Andrew Miller unproven, Josh Beckett has been the only mainstay in the rotation though the first half.