It's been discussed elsewhere, but it's not like there are great available solutions when it comes to the trade market for where the Cubs can upgrade. I would be really hesitant to tinker with the OF, SPs, and MIF, plus I'm willing to keep Busch/Bellinger at 1B for the remainder of the season since Busch has some tantalizing peripherals.
That leaves C, 3B, and RP. I'm really bearish on Bregman and Chapman at 3B since both will likely hit free agency after this season. Danny Jansen and Elias Diaz would make nice additions at C, but are the Jays and Rockies willing to deal?
As for RP, there's a fascinating crop of closers, but I'm wondering if the Cubs would be better off adding on the periphery so they can launch guys like Cuas into the sun while they wait for Alzolay to return from injury.