Well, he could kinda fill into Posey's spot, more of a midrange game, less of an outside shot, no where near the D. It would depend on whether they thought he could play mostly at the SF spot, since backup PF seems to be locked down. I'm also expecting BBD (or maybe Powe) to get traded, so there MIGHT be some minutes to be had at the PF spot in small lineups. But, not a priority, and at the price that it would make sense to make a signing Minny would match in a heartbeat.
I bet they'd match almost any contract short of full MLE or for more than three years; even if you weren't going to play him much, Gomes would have a decent amount of trade value if he's on a 3 yr/$12M-kind of contract (which is about what I think he should be getting paid).