Players refusing contracts

So, Zouma in my Career mode is refusing to negotiate a contract however hes not asking to leave the club just yet. Any contract I offer is just flat out refused.

He has until the end of the next season before his contract runs out so should I just cut my losses and sell him on or hold out and see if I can tide him over next season with a new contract. Ive got pretty decent depth for CBs (Stones, Laporte and 2 YA players with another couple youth players coming through) but he is still one of my favourite CBs to play with