Red Sox place Jon Lester on DL

The Boston Red Sox placed ace left-hander Jon Lester on the 15-day disabled list Wednesday with a strained muscle in his back.

The team recalled reliever Scott Atchison from Triple-A Pawtucket to take Lester’s place on the roster.

Lester had a no-hitter going against the Toronto Blue Jays on Tuesday, but was forced to leave after four innings because of soreness in his back. He had an MRI on Wednesday.

Lester had been one of the two consistent starters in the Red Sox rotation, going 10-4 with a 3.31 ERA so far this season and challenging the AL leaders in wins, winning percentage and strikeouts. Atchison, 35, is in his fourth stint with the Red Sox this season; he’s 0-0 with a 4.73 ERA.

Also Wednesday, slugger Adrian Gonzalez took the night off after playing in the first 85 of the season. He told manager Terry Francona he had a stiff neck. Kevin Youkilis, who was hit by a pitch and sat out Tuesday, returned to the lineup.

Francona also said he expected to have outfielder Carl Crawford back shortly after the All-Star break. Crawford’s been on the disabled list since June 18 with a strained left hamstring.

”I talked to Carl today. He’s doing really well,” Francona said. ”It’s not etched in stone, but I think what we’re going to do is wait ’til the All-Star break and then let him go play a couple of games when the break is over and then maybe join us in Baltimore rather than try to get him back here for a Sunday.”

Francona said Crawford didn’t object to a brief minor league stint after the break to get his timing back. That would also allow him to return when the team plays in Camden Yards, which has natural grass, instead of on the artificial turf when the team returns from the All-Star break against Tampa Bay.