West Ham have been fighting for survival with "50 per cent" of their team missing according to manager Sam Allardyce, who played up the impact of Andy Carroll's injury on the club's current fortunes.

The 25-year-old England international has yet to play this season after struggling to overcome two similar foot injuries, with the Hammers badly missing his contributions.

Without Carroll, West Ham have slipped to 19th in the Barclays Premier League and have been on the receiving end of cup thrashings from Nottingham Forest and Manchester City in the last week.

The former Liverpool man, who was initially on loan at Upton Park last season, is likely to be in the squad which travels to face fellow strugglers Cardiff on Saturday and Allardyce is looking forward to getting his talismanic figure back amongst his squad.

"I always say that in the end the most important thing is that your leading front man will be 50 per cent of your team or more," he said.

"It was proven to be the case for me when I signed Nicolas Anelka from Fenerbahce for Bolton. That was more than 50 per cent of the continuing success we gained from there on.

"In some cases, the squad behind Nicolas got a bit weaker than it used to be, by players getting older and retiring, like Youri Djorkaeff and Jay-Jay Okocha, but with Nicolas there we ended up competing in the Champions League spots. We've been without Andy all season. With him, we'd be an awful lot better."

Allardyce made comparisons to other Premier League clubs, in particular Manchester United, who have suffered a downturn in form with both Wayne Rooney and Robin van Persie sidelined with injuries.

He said: "If United's demise is down to some of the results not going for them, it's because Van Persie and Rooney haven't been there.

"[Manchester] City's whole team is brilliant, but they've got so many great finishers it makes it easier for them to win matches. They put the ball in the net more than anyone else.

"You can't find more than one great finisher if you're us. Even Arsenal, with [Olivier] Giroud, don't have too much more after that. What would Liverpool be without Luis Suarez? They coped very well before that, but have scored even more since he's been back. How difficult would it be without him?"

Carroll has not been rushed back into first-team action despite the Hammers not winning a league match since November but could be on the bench for the crunch match at Cardiff.

Allardyce believes Carroll is champing at the bit to return and, if he does feature, will not shirk the physical challenge of being back in action.

"Mentally he's fine," Allardyce added.

"He is frustrated and eager to get back as quickly as he can. We've had to keep him calm and focused on the time it's going to take to make sure it's right.

"I don't know whether Andy can play 'within himself'. When he's on the field, he's on the field. All thoughts of injury leave him. It's about passion for playing football."

A win would see West Ham move above Ole Gunnar Solskjaer's Bluebirds in the table but would not necessarily take them out of the relegation zone.

The Hammers are coming to the end of a full-blown injury crisis, with Carroll's return coinciding with James Tomkins and Ricardo Vaz Te approaching full fitness.

Allardyce has cited his long injury list over the festive period as the main reason for West Ham's plight and believes, with a few January additions, that his squad is good enough to survive.

"If I'd had a fully fit squad for the Christmas period and the cup games and the results had gone badly, I'd be really, really worried then," he said.

"But I'm confident we'll get the players back fitness and add to that. We've got Roger Johnson in with all his experience from the Premier League, and he knows what the task is and how difficult it is at this level. He's experienced it with Birmingham. He can also draw on his experience at Wolves."