His mental approach to the game--including his dedication and preparation--has changed (perhaps) after signing the long term, lucrative contract.
You were doing okay until this part. The Sox can only wish they had players half as dedicated as Crawford. If anything, he has been encouraged to dial it back a bit based on the relentlessness and intensity of his preparation.
I am pro-Crawford. I also recognize he isn't performing anywhere close to expectations. But the inference that he is less dedicated or less prepared as a result of the contract is preposterous.