How will the Cubs fill out the back end of the starting rotation?

Chicago Cubs could stick internal or look for a buy-low free agent option

The final realistic candidate for the rotation is Keegan Thompson. Like Steele, Thompson was stretched out after an early bullpen stint and was added to the rotation after the trade deadline. Thompson also had a K/9 of 9.3 but struggled mightily with walks, posting a BB/9 of 5.2.

Thompson began to struggle both out of the bullpen and in the rotation, looking more and more fatigued as the season wore on. The righty is likely a long shot to start the season in the rotation, but there is some potential with him, and some refinement in the minor leagues will likely be the best path for him to start the year.

The final two spots in the rotation could go any which way, and while it’s possible the Cubs add a cheap free agent, it seems more likely that they’ll rely on in-house options to fill the void. All four will have the opportunity to make their cases at spring training, and Ross and Hoyer will certainly be watching closely.

While many may think Mills could be a favorite for one of the spots, Hoyer has repeatedly stated the need for power pitchers in the rotation, which certainly favors Alzolay, Steele, or even Thompson over Mills.

However, spring training will be massive for Alzolay, and if he doesn’t show improvement against lefties, it’s unlikely he starts the season in the rotation. It’ll certainly be a compelling battle to watch, and it could go any number of directions.