Clay Buchholz emerged beaten up from his injury-rehabilitation start for Class A Lowell on Sunday but the part Boston is hanging its red socks on is that Buchholz seemed fine physically.

The right-hander who could be the key to Boston's September lasted only two-thirds of an inning throwing 38 pitches during that time. He was slated to throw between 40 and 50 pitches.

Buchholz surrendered three runs -- one earned -- as the Lowell defense made a couple of errors behind him. Three walks didn't help.

"His velocity was in the upper 80s" Red Sox manager John Farrell said. "He came out of it fine physically. That's the big thing at this point."

Boston's plan going into the day was for Buchholz to make one more rehab start on Friday and then if all was right move him back to the majors. The thinking is that with rosters expanding in September even if Buchholz only gives the Red Sox four innings in his first couple of starts back they'll have plenty of relievers to cover the rest.

Whether Sunday's shorter-than-expected stint and wildness will cause a delay in his return now is difficult to say. Farrell said he expects the Red Sox to discuss Buchholz's injury rehab program Monday to finalize the next couple of steps.