Still on the disabled list without a definitive timeline for his return to the Boston Red Sox rotation, Clay Buchholz made his first rehab appearance with the organization’s Triple-A affiliate on Saturday. The lanky right-hander looked sharp at times, but overall struggled throughout the outing.

Scheduled to throw 80 pitches, Buchholz would only get 62 in before being pulled from the game in the fifth inning with two outs. He’d allow three runs on four hits, including a pair of home runs. At least three other balls were hit hard off him during the outing, resulting in outs at the warning track in right and left field. He’d strike out five while walking none.

Most notably he appeared visibly frustrated on the mound at times.

Carlos Sanchez got things started quickly for the Charlotte Knights, tripling into the right field corner in the first. Buchholz promptly kicked the pitching rubber and slammed his glove against his leg, before inducing a ground ball that would score the runner from third.

Sanchez would again be a thorn in the 29 year old’s side, hitting a home run to right-center field to lead off the fourth inning on an 0-1 fastball. The next inning Blake Tekotte took Buchholz deep again, a liner down the first base line that just cleared the fences and ended his day.

It’s worth noting that physically he did look fine on the mound. There do not appear to be any lingering issues with his knee, if it was really the cause of his DL stint after all.

Boston initially placed Buchholz on the DL in late May, citing a hyperextended left knee as the reason though many have questioned whether that was really the cause. He’d struggled to start the regular season, prompting plenty of questions and open speculation about his ability to handle the struggles from a mental standpoint. He’d made ten starts for the Red Sox before the move, posting a 2-4 record and 7.02 ERA to go along with a 1.980 WHIP in 50.0 IP.

Buchholz had gotten off to a phenomenal start to the 2013 season before landing on the disabled list in early June, missing most of the rest of the season before he’d return to make four starts in September. Question cropped up at that time about his mental makeup and some of those appear to still be valid concerns. It’s hardly fair to blame Buchholz’ struggles on that alone, but something hasn’t appeared right about his ability to keep the ball over the plate and consistently get batters out since.