Perez repeated Round Rock .
Perez posted a respectable 4.25 ERA , but his peripherals were awful , as he struck out just 4.9 batters per nine while walking 4.0 per 9 .
Repeating Round Rock , Perez posted a respectable 4.25 ERA , but his peripherals were awful , as he struck out just 4.9 batters per nine while walking 4.0 per 9 .