Worst case scenario, sign him to a contract, showcase him, and then move him later after you inflate his value.
I think the problem is Guerin's ego is bigger than his brain. He doesn't wanna play the game. He already said he doesn't try to win trades. I don't trust him at all to actually get full value for Rossi because he doesn't value him like he should and he's not smart enough to try to get more value out of a trade.
He does the same thing with contracts. Won't budge an inch if he isn't enamored with a player, but when he is (Foligno), he'll overpay instantly as his initial offer to the guy.
I've said before, I don't think any of these things are necessarily bad qualities in a GM, but I do believe Guerin is terrible at evaluating players and and what's needed to win, and that's what makes the aforementioned a dangerous quality.