Karstens had departed his start Tuesday night after one inning, suffering from inflammation in his pitching shoulder. He will return to Pittsburgh with the club following the Wednesday matinee, but the Pirates did not await results of his examination by team doctors before making the move.
"We went through an evaluation process with Jeff with [the D-backs'] doctors last night, and looking at the best move for us, we saw no need to milk it through, to have him skip one start then reassess," manager Clint Hurdle said. "Just shut it down. He'll be thoroughly evaluated by our team doctors when we get back, but this removes any urgency and provides some clarity on how we move forward."
The Bucs' 2006 No. 1 Draft choice (fourth overall selection) could be only a placeholder for A.J. Burnett, who is scheduled to make one more rehab start -- on Saturday with Double-A Altoona -- before coming off the DL for his debut with the Pirates.
Karstens allowed the D-backs two first-inning runs in his third start. He'd overcome rough first innings in each of his first two starts to rebound with strong outings, posting an ERA of 3.27 in them.Apparently, however, the shoulder issue did not arise suddenly. "But there were no visible signs. Tonight, there were visible signs," Hurdle had said following Tuesday night's game. "The ball was not coming out of his hand like we were hoping, but he still had his game face on. "When he came in after the inning, we knew."
This is the first time in his Major League career that Karstens has had to be shelved with an arm-related issue. He spent time on the DL in 2007 with a fractured right leg, in 2008 with a strained groin muscle and in 2009 with a strained lower back.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.