I believe it is a mutual option, which provides virtually -0- leverage. I think there is a small chance, particularly if Gray beats the Yankees in the playoffs, that Gray decides he likes it here, and agrees to a small discount. He looks like a dude that doesn't let money rule his world. But we still need to put FA-level coin on the table.
As a twist, while it is extremely unlikely he ever gets to the HOF, playing for the RS will be a plus. Everyone will offer him 2 years. We can offer him 2 plus a team option will easily-attainable goals to flip that to a guaranteed 3rd year, or even a 4th year. And if he can win his 20th this year, that's one more chip on the table.