Florida right-hander Josh Johnson left the Marlins' game against the Padres on Wednesday night after five innings because of a stiff forearm, then was placed on the 15-day disabled list. Making just his fourth start after missing the first 2 1/2 months of the season while recovering from an irritated ulnar nerve in his pitching elbow, Johnson said he felt the tightness while throwing warmup pitches before the sixth inning. "It didn't get better," he said. "It was tight. I guess better safe than sorry."