Lester suffered the injury running the bases in the bottom fo the second inning in a 10-0 win against the Pirates on Monday. He then exited in the top of the third inning.
Lester will certainly miss one start and could miss two, manager Joe Maddon said Tuesday.
In a corresponding move, Chicago recalled left-hander Tim Collins from Triple-A Iowa. Collins had a 4.37 ERA in 38 appearances for the Nationals in 2018. He has a career 3.62 ERA and 1.41 WHIP in 266 big league appearances.