2. Justin Steele
I'm just gonna say it. Trading Justin Steele would be a stupid move, no matter what the offer is. In the modern game of baseball, there are so many teams who wish they had an ace-level pitcher like Steele in their rotation, not to mention one they drafted and developed. The Cubs not only have this with Steele, but they have him under team control for the next three seasons and are in a good position to lock him into a longer contract extension in the near future.
This is a guy who is in his third consecutive year of pitching at a very high level, one of which he competed for a Cy Young award. Fans love watching him pitch, he has a bulldog personality that translates to his work on the mound and he deserves to be on this team for their next playoff run.
Given his team control and high-caliber performance on the mound, it would take a king's ransom for a team to acquire Steele. Even if a pitching-needy team with prospects to deal like the Orioles or Red Sox came calling, the Cubs should reject those offers and keep Steele at the top of their rotation.