West Ham United co-owner David Sullivan admits they face a battle to keep goalkeeper Robert Green.

Green has been linked with Tottenham and Bayern Munich among several clubs this season.

"Green's contract is up this summer," said Sullivan. "We have made him a fantastic offer, subject to us [getting promoted and] staying in the Premier League. But if we don't stay in the Premier League, we won't be able to afford him and he won't want to stay. So we have to go up."