Chicago optioned struggling righty reliever Carl Edwards Jr. to Triple-A Iowa and also placed left-hander Mike Montgomery on the 10-day injured list with a mild left lat strain. Montgomery's designation is retroactive to Friday.
In their place, the Cubs recalled lefty reliever Kyle Ryan from Triple-A and selected the contract of righty reliever Allen Webster from Triple-A. Both will be available when Chicago plays at Milwaukee on Saturday evening.
Edwards' demotion comes as he has posted a 32.40 ERA in four appearances early on. In 1 2/3 innings, he has allowed three hits and walked five batters.
Montgomery was struggling as well, posting a 16.88 ERA in four appearances, over which he allowed five earned runs in 2 2/3 innings.
The Cubs signed Ryan, 27, to a big league deal in November after he had a 2.86 ERA in 22 appearances for Triple-A Iowa in 2018.
Webster, 29, had a 1.13 ERA in eight games split between Double-A and Triple-A in 2018, when he also had a brief stint with the Cubs, for whom he allowed two earned runs in three inning.
To make room for Webster on the 40-man roster, right-hander Jen-Ho Tseng was designated for assignment.