Jack Sullivan, son of West Ham co-owner David Sullivan, has confirmed the capture of Diego Poyet on Twitter.

Poyet, 19, had been expected to join the Hammers after goalkeeper Adrian tweeted a picture of himself, forward Mauro Zarate and Poyet in France for the club's pre-season training camp.

An industrious central midfielder, Poyet is the son of Sunderland boss and former Chelsea midfielder, Gus.

The Spaniard only made his first team debut for Charlton Athletic last season before informing the club he would not return for pre-season training following the expiration of his contract.