The Hammers netted four goals in the Boxing Day demolition of Portsmouth but it was the first time in 12 games they have scored more than a solitary goal in a Premier League fixture.

Ashton has been out since September after picking up a knock in training which required surgery, and Zola is missing his goalscoring prowess.

"This is the season so far," said Zola. "I've lost him, probably the best finisher in the team.

"I can't say whether he will be back in March, April, February... it depends how he progresses.

"I don't think we will have him back in January or February, but I hope soon.

"He had something causing problems with the cartilage in his ankle but because of his previous injuries it couldn't be a quick thing because they don't want to do any more damage."

Ashton's replacement, Carlton Cole, has been doing well but his goals have been sporadic and at times he has struggled to gel with fellow forward Craig Bellamy.

In the last week, the 25-year-old has been having extra one-to-one tuition with Zola, one of the classiest forwards of his time, and it paid off as he scored the second goal at Portsmouth, albeit a tap-in from a couple of yards.

"Carlton works very hard and just needs to improve on a few things around the box," said Zola.

"He's had so many chances so far and hasn't converted them but finally he did.

"He needs a bit of confidence as well and the goal today will help him a lot."

Bellamy is on the up, though, scoring twice at Fratton Park, but will not be able to add to his tally against Stoke tomorrow as he is suspended.

Speculation has been rife that he will move on next month and Tottenham are reported to have made a bid, but Zola insists he wants the combative forward to stay.

"It's a pity he is suspended because he's going through a very good spell," he said. "When he plays the way he's playing he's very important for us.

"Me, (technical director) Gianluca Nani and (chief executive) Scott Duxbury have a total understanding and are working together as a team.

"There's so much speculation but as far as I'm concerned he's our player. It's as simple as that.

"Now we have a match on Saturday and we have to focus on winning because if we don't it will cancel out what we did against Portsmouth."