West Ham United boss Gianfranco Zola admits he may face a battle to hold onto assistant manager Steve Clarke.

Clarke has attempted to bring the winning mentality of Chelsea to help Zola's start as a manager in the Barclays Premier League - and the Hammers are starting to turn the corner after a tricky start.

"Talking to me about Steve Clarke is like talking to me about my father," said Zola.

"He's such an important person for me - which is why I said since the day I took the job that I wanted him with me.

"I am a little bit worried about losing him. But my worries are completely overcome by the pleasure of seeing him going his way and having the success he deserves.

'I know one day he'll go into management and I'll be very sad. But I am going to be happy knowing he can do a great job. I would say he is my best signing."

Clarke was assistant to Jose Mourinho at Stamford Bridge, and Zola added: "They keep talking to each other. But I don't know if he gets tips from Mourinho. He knows a lot about the game and has given me his own tips."