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.

They face Tottenham tomorrow on the back of three clean sheets, which Zola feels is reward for his and Clarke's work.

"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."

Another important Hammers arrival has been Nikos Tzouroudis as head of the medical team, an apparent result being players staying fit - unlike during Alan Curbishley's regime.

Tzouroudis' appointment caused controversy at the start of the season - because he is not registered with the General Medical Council (GMC) as required by the Football Association, so cannot sit on the bench during match days.

"We nearly have everybody back, so people aren't getting injured like they used to," said Zola.

"It's another thing we're improving and it's very important.

"The players are working well, and the physios are doing a good job. When you are fit and well trained, it's very difficult for you to get injured."

Lee Bowyer is the only slight doubt for the Spurs clash, while Kieron Dyer will step up his return with a friendly this week - and Dean Ashton is due back next month.

"Dean is in rehabilitation and seeing his own physio," Zola reported.

"I know he is doing very well but I don't how long he is out. I think it might be new year but I don't know if it will be the very beginning of the new year."

Meanwhile, Zola is ready to offer Jack Collison a new long-term contract as he looks to maintain his club's policy of nurturing homegrown talent.

It is the same philosophy of Harry Redknapp, who returns to Upton Park tomorrow as Spurs manager.

Redknapp earned West Ham plenty of money in player sales, stabilised what was seen as a 'yo-yo' club and also brought entertainment by reviving Paolo di Canio's career.

It is uncertain how he will be welcomed on his return.

"I think they will give him a good reception," said Zola.

"He will get what he deserves. It's a very important game for this club, but people have to respect what others have done for the club before. I'm sure our fans will do that."