It's a very typical story. Casty's skills are in decline - he's aging. Like many star athletes, he has trouble accepting, or even believing that.
Communication? I'd wager Thomson told him something like, "You're our guy in RF." That probably happened...in 2023. In Nick's mind, he's the same player in 2025 that he was in 2023...so he should still be "the guy." He's not.
We knew, when Castellanos was signed, that the latter years of his contract were going to be problematic. Here we are.