Dyer could miss the rest of the season after sustaining the injury against Bristol Rovers on Tuesday, with his rehabilitation starting after surgery which was scheduled for today.

Upson has had his share of time on the sidelines - a broken leg, a damaged cruciate ligament and a ruptured Achilles - and he is aware of the mental aspects of getting back to fitness.

"It is a discipline thing," said Upson. "You can go into a state of despair sometimes when you look at the length of time - six months or a year out - so it is a case of getting your head together and working backwards and being disciplined in what you do, as you can quite easily lose it.

"In previous injuries I have lost the discipline a little bit but, because of the nature of the problems I have had, you work from the date that you want to be back at.

"You are in around the lads with the banter and that does not change. But you don't feel part of the team as you cant play. So you need to focus on what you need to do, and that is get fit."

Dyer's career has been beset by injury and his move to West Ham was seen as a fresh start, only for a careless challenge by Joe Jacobson to rule him out again.

Boss Alan Curbishley saw the midfielder in good spirits after the initial trauma, and was optimistic himself as the break was "clean".

"The two breaks are clean breaks and if you were going to have a best way, that's the best way," he said.

"I don't think we're going to put a time limit on it. It's obviously going to be most of the season or all of the season.

"There were other scenarios and he's come out with the best scenario."

Curbishley was still upset by Jacobson's challenge but accepts there was no intent.

He added: "I stand by what I said on Tuesday night. The player will be disappointed when he sees the challenge. I spoke to Kieron about it and we don't think it was in any way malicious.

"We think he was trying to bring him down as Kieron was trying to get away from him, and he swung out and it all went completely wrong, horribly wrong."

The Hammers went on to win the Carling Cup tie but there were barely any celebrations.

"When we found out the extent of the injury on Tuesday the dressing room went completely quiet and it was a difficult second half for us, to be fair," he added.

"That's how much it was felt in there. We all felt for him so badly."

Upson was not playing but added: "It turns your stomach, doesn't it? I think a few of the boys heard the noise, it is not pleasant.

"But by all accounts the problem is as good as it can be. I am sure that he will be back fit and strong."