West Ham boss Manuel Pellegrini has no doubts about the motivation of new signing Samir Nasri.

Nasri is set to make his debut in Saturday's FA Cup third round tie at home to Championship side Birmingham.

Pellegrini said: “Is he going to be the same player we saw at Man City? I suppose, because he knows that this is revenge for him. He is motivated, working hard.

“He must demonstrate it with his performances. He is a player whose value would be a lot of money, but we have to wait for him to play. I trust him, that's why he is here.

“He has a lot of quality and I am absolutely sure he will be a player that makes a difference. He is looking very well. He has lost some kilos in his weight.

“Football is like riding a bicycle when you are a small boy — you never forget how to do it.

“Samir is a very technical player and I am sure he will play the same way as he did before. I trust him a lot and what he will give our team. Is this his last chance to do something big? I suppose. But he can play four or five years more without any problems."