West Ham have an "unbreakable option" over the future of rising midfield star Manuel Lanzini, according to the club's co-chairman David Sullivan.
The 22-year-old has proven a revelation in the Premier League this season after arriving on a loan deal from Al Jazira, scoring three times in the top flight for Slaven Bilic's side.
One of Lanzini's goals came in the surprise 3-0 win away to Liverpool in August and reports over the weekend suggested Jurgen Klopp is looking to pounce for the Argentina youth international's signature.
Sullivan, however, has warned rival clubs off any potential bid, telling West Ham's official website: "I know there have been some reports in the media over the weekend surrounding the future of Manuel Lanzini.
"We have an unbreakable option with both Lanzini and his club, so any other team's interest is irrelevant.
"Manuel has been a fantastic signing for the club and we all hope he can maintain this superb run of form for the rest of the season."
Sullivan also revealed some encouraging news concerning the injuries to striker Enner Valencia and Dimitri Payet.
"We had some positive news on Enner Valencia's injury and are hopeful he will be back in action at the start of the New Year," he added.
"Dimitri Payet also saw a specialist on Monday and does not need surgery and will begin his rehabilitation programme immediately.
"The injuries to both players are huge losses for the club. We have a great squad, but Payet has been the star player of the season and he is bound to be missed."