Eddie Butler, a former Rockies first-round Draft pick, was designated for assignment on Saturday, the team announced.
Colorado designated the right-hander, who it took with the 46th overall pick in 2012, to make room on its 40-man roster for the newly-signed Greg Holland, the onetime Royals closer coming back from Tommy John surgery.
"We needed a [roster] spot. We certainly didn't want to take him from the roster," Rockies general manager Jeff Bridich said.
Butler has pitched the past three Major League seasons with the Rockies, including 17 appearances (nine starts) in 2016. The 25-year-old went 2-5 with a 7.17 ERA, with 21 walks and 47 strikeouts in 64 innings.
In his career with Colorado, Butler is 6-16 in 36 outings (28 starts) with a 6.50 ERA, 70 walks and 94 strikeouts over 159 1/3 innings.
Butler could still remain in the organization if he were placed on waivers, cleared and then sent to the Minors. However, Bridich also said, "It would not surprise me if there was a lot of interest in Eddie."