Tim Wakefield was shelved Tuesday with lower back strain.

A strained lower back has landed all-star knuckleballer Tim Wakefield on the 15-day disabled list.

Wakefield told reporters Tuesday he felt a "sharp pain in my glute area" when pitching on the side this past weekend.

"I had a lot of work to do [and] threw a simulated game," Wakefield said. "I felt fine, then afterward it tightened up on me.

"I'm trying to make it get better and getting treatment every day. But it doesn't seem to be going away right now."

Wakefield is 11-3 this season with two complete games in 17 starts for the Boston Red Sox, including 5-0 in his last seven outings.

But having enjoyed the all-star break and not having pitched since July 8, he opted to throw on the side to stay sharp.  

"My hips might not be aligned right," Wakefield said. "Having not thrown on the mound for a week and then getting back on the mound, it might have jarred something in there that caused a big spasm."

"We're going to try to make it be good," Red Sox manager Terry Francona explained. "We didn't want him to be hurt like this.

"Rather than push a start [back], we will try to use this to our advantage and try to get him to come back where he left off."

Wakefield is 189-160 lifetime with a 4.32 ERA, 32 complete games and 22 saves in 558 appearances (417 starts) over 17 MLB seasons with the Pittsburgh Pirates and Red Sox. 

The move to the DL is retroactive to July 18, meaning he can be activated Aug. 2 — his 43rd birthday.

With files from The Associated Press