Parker has been linked with a top-flight return ever since the Hammers were relegated in May, and Allardyce has admitted a club, believed to be Tottenham, are in talks over acquiring his services.

The former Blackburn and Bolton boss insists no deal has been done, though, and if one cannot be struck, he will keep the player at Upton Park.

"We will certainly miss a player of Parker's quality, and we want him with us if the negotiation doesn't go through," he said after his side's third straight away win.

"Whether the deal is achievable yet, I'm not sure, I've had lots of conversations with the chairman.

"But the most important thing was this game.

"If he does actually leave, I need to replace him immediately. I don't expect any other player to leave before Wednesday.

"I'm more interested in strengthening the squad, we need numbers. We need to add a few more players. The 17 I've got are very good but we need a few more."

United did not miss Parker today, though, having the game wrapped up by the break.

A Luke Chambers own goal put them in command, before Kevin Nolan and Carlton Cole headed in.

Robbie Findlay pulled one back for Forest but it was too late by then, and Winston Reid wrapped things up for the visitors.

Having struggled at home so far, West Ham have impressed on the road, adding this victory to other wins at Doncaster (1-0) and Watford (4-0).

Allardyce added: "We scored four again. It's a very unusual victory. At the second time of asking we went away and scored four. To repeat it immediately is outstanding.

"It was an outstanding performance, and showed a commitment to overcome a difficult team at a difficult ground.

"We punished them with our quality in the final third and took full advantage of the excellent delivery of the ball into the box.

"At Upton Park there's too much anxiety, we're feeling more comfortable away from home.

"It's understandable with some of the players' memories of last season.

"But that's three away victories on the trot."

Forest manager Steve McClaren blamed poor defending for the defeat as his side continue to search for a first home victory this season.

The former England manager has struggled to spark last season's play-off semi-finalists so far, and said: "I think we were the creators of our own downfall, because at 3-0 down I thought we had played well.

"We created chances but football is a simple game, it's what you do in your own box and what you do at the other end.

"We defended very poorly. We had opportunities in the other box.

"Today our weaknesses got exposed. It's up to us to address that on and off the field.

"You go nowhere with defending like today. We can defend better than this. But not many teams can exploit you like West Ham.

"They are my favourites for this league, they are a Premier League team with Premier League players so it was a good test for us today."