The Royals reliever made his first appearance of the season in Sunday's 13-7 loss to the Indians, but he wasn't even on the 25-man roster the previous day.
After nearly emptying their bullpen on Saturday, the Royals called up Coleman for Sunday's game, and he entered the game in the sixth inning. He went three innings, giving up three runs on three hits and two walks.
Coleman held the Indians, who had already put nine runs on the board, scoreless through his first two innings of work before surrendering home runs to Casey Kotchman and Jason Kipnis on back-to-back pitches in the eighth.
"Some good things and some bad things, positives and negatives," Coleman said after the game. "A couple bad pitches. You can't get them back. Just learn from mistakes and try to move on."
Coleman said he was alerted during extra innings of Triple-A Omaha's game in Albuquerque on Saturday night that he'd be heading to the big league club the next day. The right-hander woke up Sunday morning, flew to Kansas City and came right to the park, arriving right as the Royals were wrapping up batting practice.
Manager Ned Yost said after the game that Coleman's outing was important for his bullpen moving forward.
"Coleman saved us today," Yost said. "We got through that game without having to use [Kelvin] Herrera, [Tim] Collins, [Aaron] Crow, [Jonathan] Broxton and [Greg] Holland on back-to-back days. If I had to use one of those guys, they'd be unavailable for [Monday's game], so we should have a fairly stocked bullpen."