The move made room on the roster for Tyler Chatwood -- who will be recalled from Triple-A Salt Lake to pitch in Monday's series opener against the Cleveland Indians -- and Scott Downs, who will be activated on Monday from the disabled list, where he was placed with a left toe fracture.
With Chatwood pitching on Monday, Dan Haren will now start Tuesday's game -- after he made a one-inning relief appearance on Saturday.
"He is one of our young pitchers and is a guy who has really come on the scene quickly for us," Angels manager Mike Scioscia said of Chatwood. "He pitched very well for us this spring, and he is one of the young arms we are very excited about."
While Chatwood has pitched only one inning this season for Salt Lake, he pitched in 27 games last season between Class A, Double-A and Triple-A, going 13-9 with a 2.84 ERA.
Downs, who has been on the DL since March 30, is expected to add more depth -- along with a fresh arm -- to the Angels' overworked bullpen.
"He is going to give us more balance. He has a great presence in the bullpen," Scioscia said. "We have been waiting for Scott to get healthy, and now he is ready to go and gives our bullpen a deeper look."
Scioscia sees this time for both Jepsen and Kohn as a way to work on improvements in their mechanics and pitch efficiency.
Jepsen needs to be able to control counts better, while Kohn needs to get his slider back to where it was in the spring, along with both still needing to focus on fastball command Scioscia said.
While he hopes the improvements in both relievers will be quick fixes, Scioscia's decision still shocked Jepsen.
"It definitely caught me by surprise," Jepsen said. "It's always a tough pill to swallow."
In five games this season, Jepsen has pitched four innings, giving up three runs on six hits with a 6.75 ERA. Kohn, also in five games this season has pitched 3 2/3 innings, giving up three hits and two runs for a 4.91 ERA.
Quinn Roberts is a contributor for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.