The Cubs were looking to upgrade at catcher since the end of the 2014 season, and tried to get Martin through free agency (but he signed with Toronto). Montero could end up being an even better fit for Chicago, as he'll be a sound left-handed batter somewhere in the heart of the order (likely hitting fifth or sixth). He's also pretty good defensively and a leader-type. With Montero in the fold, look for Chicago to trade Castillo to shore up other areas.

The D'backs don't really have a starting catcher to replace Montero, but they clearly don't view that as a pressing concern at present time. Instead, they accepted the Cubs' offer of two young pitching prospects--one starter and one reliever. Mejia is the key to the deal, but he's only 19 and several years away from contributing. Still, he's 6-7 with huge upside. As for Godley, he's also a big right-hander with late-inning reliever appeal and potential. He's 24, so he may move quickly.

Montero's fantasy value should move in the right direction now that he's going to be the main backstop for the up-and-coming Cubs. His power stroke worked well in Arizona, though, so he must prove he can handle the Windy City. Mejia has obvious keeper-league appeal, but he's not yet a major factor. Godley has an outside chance of reaching the big leagues in 2015, so he's a dark horse for saves/holds in fantasy baseball.