Right-hander Rob Whalen was optioned back to Tacoma to make room for Bergman on the 25-man roster and started Sunday's game for the Rainiers. Since Bergman had to also be added to the 40-man roster, reliever Shae Simmons was transferred from the 10-day disabled list to the 60-day DL to open a spot there.
"Another day, another new guy," Mariners manager Scott Servais said before the victory. "It's the state of where we're at right now, just trying to make the best of what we've got. That's why the roster was put together the way it was, so we could shuffle some of these guys back and forth. And we've been doing it."
With their rotation suddenly relying on fill-in starters Chase De Jong and Dillon Overton, Bergman offers a long-relief option with big league experience. The 29-year-old pitched 55 games for the Rockies over the last three seasons, including 15 starts, compiling a 7-9 record and 5.79 ERA.
Bergman has pitched extremely well for Tacoma this season, going 5-0 with a 2.17 ERA in five starts. Sunday was his next scheduled start, so he's available to pitch whenever needed.
"Whatever they need me to do," Bergman said before the game. "I did a lot of [long relief] with the Rockies, all of '15 and most of '16. I had a spot start here or there, but that's the bulk of what I did. It can be tough at times, but having done it a little bit already, I kind of know what to expect and little things to do to stay ready."
Whalen was recalled on Saturday to provide a similar long-relief option, but De Jong threw six innings in his second start in place of Felix Hernandez and the Mariners didn't need much help in an 8-2 win over the Rangers.
With Hernandez and James Paxton both on the 10-day DL, the Mariners have had to juggle their rotation recently. Additionally, Hisashi Iwakuma's next start has been pushed back two days to Thursday due to a sore left knee. The club is also without Drew Smyly, who is on the 60-day DL with a strained left elbow that sidelined him just before the start of the season.
Simmons hasn't thrown since injuring his right elbow early in Spring Training. He was acquired from the Braves during the offseason.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.