The Chicago Cubs might be without starter Jake Arrieta for some time. The ace left Monday's start against the Pittsburgh Pirates in the third inning with what appeared to be a hamstring injury. He attempted a few warm-up pitches after said injury, but was not able to go. 

Arrieta has had somewhat of a down season, pitching to a 14-8 record with a 3.36 ERA. But he is coming off a month of August in which the former Cy Young winner posted a 4-1 record with a 1.21 ERA.