"He went back to L.A. for an MRI," Dodgers manager Joe Torre said. "He was warming up and he stopped himself."
Ohman, a free agent in a chilly market for relievers, was signed to a $1.35 million contract with an option for 2010 with one week left in Spring Training. At the time, the Dodgers were concerned about their left-handed bullpen depth because Hong-Chih Kuo, last year's dominant setup man, had a tender elbow and the group of non-roster invitees was lackluster.
The Kuo concerns proved valid, as he made only seven appearances with a 6.75 ERA before going on the disabled list April 30 with no sign he'll return soon, if at all.
However, Ohman wasn't the answer either, knocked around for a 5.84 ERA in 28 appearances before going on the disabled list.
Rookie Brent Leach, meanwhile, has become the unexpected situational lefty, making 22 appearances with a 3.38 ERA since being promoted May 2 from Double-A Chattanooga.
In other rehab updates, Torre said Claudio Vargas appears healed from his right elbow injury and his rehab assignment must end next week, so the club will need to make a decision on activating him. Torre said he is best suited for a swingman role along the lines of Jeff Weaver.
Right-hander Jason Schmidt had an effective start for Albuquerque earlier this week and left-hander Eric Stults has returned to California to make his first rehab start at Class A Inland Empire on Thursday for his sprained left thumb.
Outfielder Xavier Paul is still nursing a sprained right ankle.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.