"He can't get over the hump," said Padres manager Andy Green. "I would assume at this point in time ... it's increasingly unlikely that he pitches for us this season. He's going to get [his elbow] evaluated again."
Friedrich, who led the Padres in starts last season, began experiencing general arm soreness in Spring Training. He missed time with a shoulder ailment during camp, then he began feeling elbow tightness during his initial recovery.
Friedrich wouldn't appear in Minor League game action until June, and after four starts, he was shut down. He returned on July 31 and pitched three scoreless frames for Lake Elsinore.
Then, on Monday, Friedrich exited his start after 4 2/3 innings. His elbow soreness lingered into the following day, and the Padres opted to shut him down once more.
In 24 appearances (23 starts) for San Diego last season, Friedrich posted a 4.80 ERA and a 1.42 WHIP.
AJ Cassavell covers the Padres for MLB.com. Follow him on Twitter @ajcassavell. This story was not subject to the approval of Major League Baseball or its clubs.