Perez's 3.52 ERA this season is right in line with his career mark (3.64), but he's been throwing slower than usual and he's walked as many as he's struck out. This injury sounds minor, and Perez figures to return fairly soon to his role as the Tribe's top lefty setup man.
Still, his performance this season underlines his decline. In 2007 and '8, Perez posted a combined 2.76 ERA and struck out nearly four times as many batters as he walked. Since then, he's got a 4.26 ERA and a poor strikeout-to-walk ratio (1.44). Essentially, Perez used to have a good fastball and a great slider, and lately he's been reduced to a token fastball and a good slider.
Lefty Nick Hagadone's been recalled to take Perez's place on the roster; frankly, Hagadone's probably better than Perez anyway.