Yes, and we got oodles of cash for him, so we didn't have to release him when his contract ran out (as happened with Shenton). Simples.
Pssst! Wanna buy an award winning stand-off with four years left to run on his contract? I'm sure we could come to some arrangement. Know what I mean? Wink! Wink!
Westerman was under contract but wanted to leave so he was sold for a substantial fee. What is to stop Chase doing the same? The contract means that if he does leave, Cas can command a sizeable fee for him.