Manager Ned Yost decided to go with Smith instead of lefty Everett Teaford in the rotation for now. Teaford is back in the bullpen as a long reliever, his original role this season.
"We want to see Will Smith continue to develop. He's a 22-year-old left-hander who we think has a chance to be a solid back end of the rotation starter at the big league level on a real good team," Yost said. "Teaford fits better long right now."
On the subject of long relievers, Yost sees that as a "perfect" role for right-hander Luis Mendoza "on a championship team." But with the Royals not in that category just now, Mendoza is in the rotation and doing quite well.
"We're trying to get on a bit of a roll and our pitching's been so spotty that we can't afford to take him out right now because he's throwing really well and we don't have a better option," Yost said.
Earlier in the season, Mendoza seemed to have trouble getting through an opponent's lineup the third time through, but that's become less of a hazard recently and Yost credits catcher Salvador Perez for the improvement.
"I think that's more to do with Sal coming back, the way Sal sets up the game and calls the game," Yost said. "His run started when Sal came back."
In Mendoza's last four starts, all with Perez calling the pitches, he had a 2.93 ERA and a 2-2 record. He's pitched eight, six, 7 1/3 and 6 1/3 innings in those games.