Royals manager Ned Yost said Friday that rookie left-hander Danny Duffy will likely be shut down after his next start Tuesday against the Athletics. Duffy has logged 141 innings between the majors and minors this season, so he is very close to reaching his limit for the year. The 22-year-old left-hander pitched 126 2/3 innings in 2009, but only 62 1/3 innings last year due to personal issues and a minor elbow injury. He has a 5.73 ERA and 88/43 K/BB ratio through his first 19 major league starts.