Manager Walt Weiss called on Bettis first following Tommy Kahnle's scoreless 1 1/3 innings. In his first appearance since being recalled on Monday, Bettis allowed three runs on four hits and a walk in one inning.
Martin took over in the seventh and struck out one in his scoreless frame, making Weiss' decision easy.
"It's just a situation where we had nine guys in the 'pen the last couple of days," said Weiss. "Someone had to go to make a spot for Matzek. Chad ended up being the odd man out."
Weiss refused to put too much stock into one rough appearance, but Bettis hasn't found success in the Majors all season, with 16 earned runs in 14 1/3 innings. Weiss is hoping Bettis can continue the success he found in Triple-A, where he's struck out 20 and given up five runs in 21 2/3 innings.
"To be fair, it was one outing for Chad," said Weiss. "We feel like he has made a lot of progress in his time down there in Triple-A."
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. Cody Ulm is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.