West Ham manager Manuel Pellegrini admits record signing Felipe Anderson’s performances need to improve.
Anderson was signed from Lazio in the summer but has yet to justify his £42million fee.
The Brazilian forward was substituted at half-time during Wednesday night’s Carabao Cup defeat by Tottenham after another anonymous display.
He has scored just one goal this season and has completed the full 90 minutes for his new club on only five occasions.
Pellegrini admits he has not seen the best of Anderson yet, and also revealed the player is not satisfied with his impact so far.
“Happy with his performances? In a way, I am not happy,” said the Hammers boss.
“I think Felipe is not happy, I think everyone is not happy. He has demonstrated he can do more.
“He has good moments in games, bad moments as well, but he is not the first player who will need some time to adapt to the Premier League.
“What I don’t have any doubt about Felipe is his commitment to the team, his performances he knows he must improve but he is giving his best.
“I trust him a lot – he is a player that can make mistakes but give you different things also.”
Nevertheless, Anderson is poised to start in attack against Burnley on Saturday alongside Marko Arnautovic.
Austrian striker Arnautovic has been playing through the pain of a knee injury and trained only once last week.
But Pellegrini insists the problem is manageable and that West Ham’s key player this season does not require an operation.
“In this moment we are managing with the medical staff to try and give him a little bit more rest after the game,” he added.
“Last week he worked just one day, with his knee and then with a virus, so it was not good for him to play on Wednesday really.
“I was just talking with him and his knee is improving a little bit every week. No, it will not need surgery.”
Pellegrini expects Jack Wilshere and Andy Carroll, who have been sidelined by ankle injuries, to be available after the next international break.