With Kansas City's Vin Mazzaro 1) pressed into relief duty Monday night, 2) giving up 14 runs in less than three innings and 3) earning a return ticket to triple-A Omaha, the Royals suddenly have an opening in their rotation, as Mazzaro had been scheduled to start Wednesday night against the Rangers.

In Mazzaro's place, Bob Dutton reports, the Royals will turn to left-hander Danny Duffy, the club's No. 1 pitching prospect and one of the six or seven best pitching prospects in the minor leagues.

Just a year ago, Duffy was out of baseball. He simply quit the game in March 2010, saying he wanted to reassess his life. But Duffy returned to the Royals in June, pitched brilliantly at four different levels -- finishing with seven Class AA starts -- and began this season with Triple-A Omaha. Duffy gets his fastball into the mid-90s, features a solid change-up and breaking ball, and controls the strike zone; this spring he's struck out 43 hitters and walked 10 in 36 innings.

Duffy's taking Mazzaro's rotation slot, which had been Bruce Chen's before Chen went on the Disabled List. At last report, Chen was expected back in early June and the Royals will certainly make room for him. But considering Kyle Davies' 7.46 ERA and his shoulder soreness, it's highly likely that if Duffy pitches at least decently for the Royals he'll remain in the rotation for a while. That said, he's never thrown more than 127 innings in a professional season and threw only 62 last year. So at some point the 22-year-old will probably just be shut down or shifted to relief duties.