Clay Buchholz threw off a mound today for the second time since June 8. But he cut short his session after only about 18 pitches and was sent for an MRI.

Buchholz is on the disabled list with what the Red Sox have said is a sore trapezius muscle.

“When he got on the mound and started to really get into his bullpen, he still feels some restriction in that same area,” manager John Farrell said.

Farrell said it was a positive that Buchholz has thrown with “some intensity” for two consecutive days. But the fact he could not complete a bullpen session is troubling.


“He’s not at the point of a normal bullpen in advance of any rehab start,” Farrell said. “His own words were, ‘It’s not ready.’ ”

The MRI will be to “better understand” what Buchholz is dealing with according to Farrell.

It seems surprising that Buchholz has not previously had an MRI given that he was injured two weeks ago. The righthander is 9-0 with a 1.71 earned run average. The Sox are 11-1 in the games he has started.

The Sox still believe it’s a trapezius issue and not something more serious.

“By all his symptoms and what’s been discovered through exam, yes,” Farrell said.

Buchholz will need to throw at least two pain-free bullpen sessions before getting into a minor league game. He also could need more than one rehab game to regain his arm strength and command.

Given those requirements, Buchholz may not rejoin the rotation until after the All-Star break.

“Until he’s symptom free, then we can plan accordingly,” Farrell said.