One of the biggest problems I've had in making these Cubs-Mariners trades is making a trade that the Mariners would actually do (lol). So let's give them an elite prospect that the Cubs truely don't really need. Caissie's strikeout rates are concerning, but he does have massive power and a great arm. I shouldn't have to explain why the Mariners do this trade, but Caissie has played an entire year in AAA and has been great. So why do the Cubs give up this great prospect? Let's look at the return: Luis Castillo and Gregory Santos. Luis Castillo is a pretty great pitcher who's value is lowered by his contract. Cubs have around $40 million to spend before they reach last year's payroll, and they will easily spend half of that to cement their rotation. Additionally, the Cubs would get a great reliever in Gregory Santos, who didn't have the best ERA in 2024, but all his other stats were pretty elite and show that he just got really unlucky. The Cubs would give up a very good, but expendable top prospect to really help their pitching problems. Additionally, trading Caissie wouldn't force them to trade Bellinger if they didn't want to (although it seems like they will whatever happens).