Padres placed outfielder Mark Kotsay on the 15-day disabled list, retroactive to May 13, with a tight lower back. Kotsay had to exit last Saturday's game with tightness in his lower back. San Diego kept expecting him to make it back, and avoid a DL stint, but with Kotsay's injury history that was probably wishful thinking. Kotsay is eligible to return a week from Sunday.