KANSAS CITY, Mo. -- The Royals purchased the contract of right-hander Roman Colon from Triple-A Omaha and optioned first baseman Clint Robinson to the same club before Thursday night's game against the Milwaukee Brewers.
Kansas City also shifted left-hander Danny Duffy, who had Tommy John surgery this week, to the 60-day disabled list and signed second-round draft pick Sam Selman to a contract.
The Royals brought Robinson up from Omaha to provide an extra bat when they play in National League parks, something they'll do again this weekend in St. Louis. They optioned Louis Coleman to make room for him, which means they've ultimately swapped Coleman for Colon.
Royals manager Ned Yost said that he needed another arm for the bullpen after using his relief corps heavily the first two games of their three-game set against Milwaukee.
Coleman has a 3.15 ERA in 20 innings of relief this season. Colon is 8-10 with a 5.12 ERA in the majors, where he hasn't pitched since 2010.
Selman, a left-hander out of Vanderbilt, was the 66th overall pick in last week's draft. He went 9-3 with a 3.55 ERA during his junior season for the Commodores.
Kansas City has now signed 28 of its 40 selections, including the first 11 picks.