Reds placed 3B Scott Rolen on the 15-day disabled list, retroactive to June 21, with a strained left shoulder. Rolen had missed two of the previous three games. He had the same injury when he was placed on the disabled list in late-April, so the lingering soreness is a pretty good explanation for his lousy .242/.279/.397 batting line. Miguel Cairo will make the start at the hot corner Friday, though Todd Frazier figures to get some playing time.