Because of a mild chronic strain of the ulnar collateral ligament in his left arm and weakness and stiffness in his left shoulder, Francisco Liriano will be out indefinitely. Twins doctors Dan Buss and John Steubs looked over results of an advanced MRI exam on Thursday before diagnosing the problem. Liriano, already on the 15-day disabled list, will immediately begin rehabilitation and won't resume pitching activities until the soreness is gone. "It wasn't worse than I expected," Liriano said. "I don't think it's a big deal. My shoulder is tired and weak, I'm going to make it stronger and come back."