Left-hander Donnie Joseph, who was belted for six runs in his first appearance this season in Monday night's 11-8 win over the Tigers, was optioned to the Pacific Coast League club.
Coleman was sent down on June 2 after posting a 6.27 ERA in 17 relief appearances for Kansas City. He'd also given up 24 hits and 11 walks in 18 2/3 innings, so he was told to concentrate on throwing strikes.
"And he needed to get his slider a little tighter, it was getting big and loopy and flat," manager Ned Yost said.
In five games with Omaha, Coleman was 1-0 with two saves and a 2.16 ERA. He struck out 10, walked just one and gave up three hits in 8 1/3 innings, making the rounds in his two weeks away.
"I went to Round Rock for a day, Omaha for four, then Fresno and Sacramento," Coleman said. "It was much better."
Coleman also tightened up the mechanics of his delivery.
"Everything feels good. It was very beneficial," he said.
Joseph was called in to finish off the ninth inning with an 11-2 lead in the series opener, but lasted only two-thirds of the inning, giving up five hits including J.D. Martinez's grand slam. Not a good thing.
"Not when you're trying to give your closer a day off and he's got to get up and get hot quick," Yost said.
Closer Greg Holland had to jump up and start throwing.
"He had to, we were one hitter away from a save," Yost said. "If [Michael] Mariot doesn't get that guy out, Holly's got to come in. That's three out of the last four days -- he's pitched one, but the other two he had to get hot with leads."
Mariot struck out the only hitter he faced to end the game.
So Joseph, after his 30-pitch nightmare, was sent away. That was his first game in two callups this year. He did much better in six Major League outings last season, working 5 2/3 scoreless innings.
Joseph, in 17 games with Omaha this year, has a 3.91 ERA, a 1-1 record and one save.