West Ham United U21 coach Nick Haycock was delighted with Sebastian Lletget in victory over Sunderland.
The American midfielder was named captain for the game.
Haycock told whufc.com: "I just wanted to give Sebby that extra bit of responsibility and I think that helped him. He is a good footballer, he knows what he needs to work on and he needs to go away for the summer and come back for the final year of his contract to show what he's actually capable of.
"He does it in fits and spells in a game, but he needs to realise he can dominate a game because he's got fantastic footballing ability, but the ability without the desire and the responsibility, it won't get him over the line. If he can develop that, then we're hopeful he could be one that could push on."
