Fernando Torres has a hernia that could require surgery if he is overplayed, Rafael Benítez has been warned.

Liverpool’s medical staff delivered the worrying prognosis during the build-up to the club’s crucial Champions League match against Lyons tomorrow night.

Steven Gerrard is definitely out of the group E tie at the Stade Gerland because of a groin problem. The Liverpool captain is joined on Benítez’s lengthy casualty list by Fábio Aurélio, Albert Riera, Martin Skrtel and Martin Kelly.

Torres has been included in the squad that travels to France today and is likely to start tomorrow’s game — when anything other than victory will leave their hopes of qualifying for the knockout stages hanging by a thread — and play through the pain.

The inguinal hernia has been affecting the striker for most of the past month since the problem developed while on international duty with Spain in early October.

Liverpool have attempted to mask the severity of Torres’s condition by nursing him through matches and allowing him to train only immediately before games, when his physical condition is deemed good enough. Since the 25-year-old suffered his latest setback, though, there have been real fears that he could need an operation.

It is hoped that the combination of rationing the striker’s appearances and occasionally allowing him to miss training will allow Torres the rest time he needs for surgery to be averted.

Benítez is aware, however, that even these precautions may not be enough to spare his £22 million record signing from having to have an operation.

Torres was substituted after an hour of Liverpool’s 3-1 Barclays Premier League defeat away to Fulham on Saturday, a decision that puzzled many fans and caused Ronnie Whelan, the former Anfield captain, to call for the manager’s head.

But it now seems clear that it was simply the latest example of Benítez’s desire to protect the forward from exacerbating the seriousness of his condition.

“I was surprised with the critics after the game because Fernando has had problems in the last month after the international games,” Benítez said. “We are trying to manage because he was close to having an operation.

“He is not comfortable. He has not got the power he had before, so we have to manage and try to protect him. He cannot play well if you keep pushing him. Maybe if you push him he will be injured for a long time.

“So, I am really surprised with the critics. When you talk about big names, people just analyse the names and not how the player is when he is on the pitch. He was not 100 per cent fit. We have to take Fernando to Lyons because we don’t have too many options.”

Benítez already faces the prospect of Gerrard having to undergo groin surgery to correct a problem he suffered while on duty with England.

“Gerrard won’t travel to Lyons,” Benítez confirmed. “He has no chance. He is improving but we have to wait. He has had an injection but we have to wait two or three days and see how he reacts.

“Skrtel also has no chance. He has a small muscle problem. It’s not too big but he is feeling something.”

At a time when Benítez’s position as Liverpool manager is being questioned like never before after six defeats in their past past seven games, his injury concerns are mounting.

The situation is so dire that Alberto Aquilani, the Italy midfield player, has been added to the squad despite not having fully recovered from illness, while Benítez has also been forced to call on David Ngog and Daniel Agger even though the pair are nursing slight knocks.

“Agger is improving — he will travel and we will then decide,” Benítez said. “He felt something in his back but it’s much better now. We have to wait and see how he reacts. Ngog is much better, so he could be available.”

Benítez has taken the unusual step of naming a 20-man squad, with Stephen Darby, the 21-year-old right back who has never started a game for the club, included in case Glen Johnson fails to recover from the calf strain that has kept the England defender out of action since Liverpool’s victory over Manchester United nine days ago.

Uefa has also given the club special dispensation to promote Danny Ayala, the 18-year-old centre back, into the squad from their B-list.