Jack Sullivan, son of West Ham United co-owner David, has confirmed the permanent signing of Manuel Lanzini on a four-year contract on Twitter.

The 23-year-old Argentine, who is on loan at Upton Park from UAE side Al Jazira, has been a revelation this season for Slaven Bilic's side.

He scored his fifth Premier League goal of the season in Saturday's 2-2 draw at Chelsea, a tally which has come in just 16 top flight starts.

Lanzini moved to West Ham on a season-long loan in the summer and, according to Sullivan, has now signed a four-year agreement with the Hammers with the option of two further years.