Adcock and Coleman both have been up with the Royals previously this season. Adcock has a 0-3 record and 3.12 ERA in nine games, including two starts. Coleman is 0-0 with a 4.91 ERA in 17 games. Mazzaro departed for Triple-A Omaha with a 3-3 record and 5.70 ERA in eight games, including a start Tuesday night in Toronto.
Second baseman Chris Getz and outfielder Lorenzo Cain are rehabbing with Omaha and are eligible to return, but that probably won't happen until after the All-Star break.
Yuniesky Betancourt has been playing second base and, through Tuesday, had 19 RBIs in his last 14 games.
"Yuni's doing fine. We'll probably get through the All-Star break and then make a move," Yost said.
Jarrod Dyson and Jason Bourgeois are currently platooning in center field, which was Cain's position coming out of Spring Training. But Cain was injured in the season's fifth game and has yet to return.
"I'd like to see him play three or four days in a row before we make a determination that he's ready to come back," Yost said. "He's doing OK. He's swinging the bat really well, playing good in the outfield, running the bases OK."