3. Caleb Kilian
Caleb Kilian has been making spot starts periodically throughout the year to little avail. I think this would be his last opportunity at the big leagues with the Cubs so I say let him try one last time. If he fails, then maybe keep him in the bullpen as a long relief option. Kilian has one more option left so they can call him up and if he doesn't perform he can get sent down with no harm done. But he does need to perform this time because at one point, Kilian was the best pitching prospect in the system and it would be a shame to see him go the way of a DFA. Especially because he was a highly touted piece of the Kris Bryant trade.
His struggles aside, Kilian is an option to start this week and the Cubs should consider it. He has been better at Triple-A recently, where he's gotten his ERA down to 3.87 on the year in 18 starts.