CHICAGO _ The Cubs placed left-hander Jon Lester on the 10-day injury list Wednesday and promoted left-handed reliever Tim Collins from Triple-A Iowa.
Lester strained his left hamstring running the bases in the second inning Monday against the Pirates. His placement on the IL is retroactive to Tuesday, and he's eligible to return April 19.
The 5-foot-7, 170-pound Collins, 29, posted a 3.38 ERA in three appearances at Iowa. Collins is 12-17 with a 3.62 ERA over 266 major-league appearances with the Royals (2011-14) and Nationals (2018). The Twins released him in March.
