Jon Lester was not long for Saturday's 5-3 loss to the Giants, yielding five runs on six hits over 2 2/3 innings.
Jon Lester gave up just one run in 6 2/3 innings but took a loss Sunday against the Pirates.
Jon Lester allowed three runs over six innings in a win over the Padres on Tuesday.
Monday's game between the Padres and Cubs was postponed due to rain.
Jon Lester tossed 5 2/3 scoreless innings Wednesday in the Cubs' 6-2 victory over the Pirates.
Jon Lester struck out 10 batters while yielding just one run over seven innings in Friday's 6-1 win over the Braves.
Jon Lester picked up his second win of the year, holding the Reds to just five hits and one run over seven innings of work on Friday night.
Jon Lester allowed just one run over 7 1/3 innings Sunday but took a loss versus the Rockies.
Jon Lester pitched six innings of three-run ball in a no-decision Monday against the Reds.
Jon Lester turned in a sharp outing in Tuesday's win over the Angels, hurling seven innings of one-run ball while striking out four.
Jon Lester was in midseason form in Wednesday's win over the Rockies, striking out 10 in five scoreless innings of work.
Jon Lester allowed just two hits over five scoreless frames against the Brewers on Friday.
Jon Lester yielded two runs -- one earned -- over five innings Saturday in the Cubs' defeat of the Royals.
Jon Lester is dealing with a bone chip in his left elbow that could eventually require surgery.