West Ham keeping hold of midfielder Manuel Lanzini - David Sullivan

West Ham co-chairman David Sullivan has warned off rival clubs interested in signing rising star Manuel Lanzini.

There have been reports of Liverpool weighing up a move for the Argentina midfielder following an impressive start to life in the Premier League.

Lanzini has scored four goals this season, including one against the Reds in West Ham's 3-0 win at Anfield in August.

The 22-year-old moved to Upton Park in the summer on a season-long loan from United Arab Emirates side Al Jazira, and Sullivan insists his club have the conditions in place in the contract to sign him permanently.

"I know there have been some reports in the media over the weekend surrounding the future of Manuel Lanzini," Sullivan told the club's website.

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"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 confirmed forward Enner Valencia will be out until early January with the ankle injury he suffered against Everton on November 7.