What It Means:

Arrieta suffered a strain of his right hamstring on September 4th. He returned on September 21st and made a short start on the 26th, but he's still dealing with discomfort and may not be at 100%. He will go through a bullpen session on Wednesday prior to the Cubs making an official announcement on their rotation. If Arrieta does pitch Game 3, look for a combination of Jon Lester and Jose Quintana in Games 1 and 2.

Arrieta's 2.51 nERD ranks behind both Quintana (2.89) and Lester (2.71). Across 6 career postseason starts, the righty is 4-2 with a 3.64 ERA and 11.4 strikeouts per 9 innings.