Susac is the only realistic option, but he wouldn't be better than Suzuki the next two years. And unlikely the Giants would move him unless they got a quality big leaguer at a position of need, which would be Plouffe. And that's not happening. Twins might consider acquiring a catching prospect if they collapse and start selling, but they are going to roll with Suzuki for the remainder of this season, and he is probably a top 15-20 catcher in the league at the moment, so they can live with that.