The D'backs have operated with a three-headed closer committee of Andrew Chafin, Scott McGough, and Miguel Castro, who each have 7-8 saves. Of course, having three closers is sort of like having two starting quarterbacks. If you have two, you really have none.
What could Arizona do to address this issue? Why not throw Hicks into the mix and add another reliever to their bullpen hydra? While it's been rumored the Diamondbacks would like to pick up an established closer, it's possible they can't find one that fits and would have to "settle" for four co-closers to shut down opponents over the last few innings.
Turning once again to acquisition cost, the idea of the Cardinals including a starter (Montgomery or Flaherty) would serve Arizona well. They've been running out a variety of young starters - Ryne Nelson, Drey Jameson, Tommy Henry, and Brandon Pfaadt - with Henry the only one providing passable results so far.
The return for such a pairing? Well, Druw Jones and Jordan Lawler aren't leaving Arizona's system, though the Cardinals already have a glut of outfielders and middle infielders. Any of the above-mentioned struggling young starters would be appealing for a St. Louis squad that President of Baseball Operations John Mozeliak said is looking for "Pitching, pitching, pitching."
Perhaps a couple of months in the pitcher-friendly Busch Stadium would help a newly-acquired youngster get more comfortable on the mound and better prepare them for next season. It's certainly a shot worth taking.