Fernando Torres is flying, but injury-hit Liverpool are heading for a crash

Those delighted fans who applauded the sight of Fernando Torres boarding flight BD7975 to Lyon, might just have tempered their excitement had they looked two rows further back.

The dedicated Liverpool supporters who pay to travel with the team into Europe were relieved, in the extreme, to see their star striker present for this vital Champions League trip.

Yet just beyond him on the plane, standing awkwardly in the aisle for almost all of the flight, was Daniel Agger, desperately trying to ease the pain in his back which forced him to miss the match at Fulham at the weekend.

While Torres may yet solve the striking problems that have dogged Liverpool in his absence this season by declaring himself fit, it is in defence that the Reds have their biggest problems.

Manager Rafa Benitez has been remorselessly criticised for the lack of depth in his squad, and particularly for failing to find adequate cover for Torres, despite having Peter Crouch, Craig Bellamy, Robbie Keane, Fernando Morientes, Djibril Cisse, El Hadji Diouf, Robbie Fowler and Florent Sinama Pongolle at various times under his charge.

Yet this evening in the gastronomic capital of France, Benitez may well become the plat de jour to be devoured by the critics, because of the crippling injury crisis that has decimated his options in a back line that has never had its depth brought into question. His response is a phlegmatic as ever.

“With the virus that we have had at the club, we have been without maybe 14 players, and I think that any top side in the world, if you lose four or five of your first team and four or five of your back up players, you will struggle,” he explained.

“Now is not the time to panic. You know you will have some bad moments in situations like this. You need to wait, be patient and see the bigger picture when good things will arrive.

“The injury situation will change, maybe in the next few days or the next few weeks, and when we get players like Gerrard and Torres back, then things will feel very different.

“People have criticised us for our lack of depth, especially with the forwards, but when you plan at the start of the season, you cannot account for injuries like this. We had back up for Torres in our plans, we had depth in defence, but we have had four centre-halves injured, and you cannot accommodate that.

Glen Johnson and Martin Skrtel didn’t even travel due to calf and ankle injuries, and neither did Martin Kelly, who deputised so ably for Johnson when Lyon visited Anfield a fortnight ago. Fabio Aurelio is out and Andrea Dossena has not played for a month due to injury, while Phillip Degen was not named in the Champions League squad.

So the sight of Agger, likely to start, standing throughout the journey to France was worrying in the extreme for a manager who knows that his own position will be brought starkly into focus should Liverpool lose tonight and effectively go out of the Champions League at the first hurdle.

The consequences of such a scenario are almost unthinkable. Not only will Liverpool lose upwards of £30million in potential TV revenue and prize money,  it will also plunge them into full-blown crisis.

The ownership model Liverpool’s American buyers have pursued - which is basically the same as that employed by the Glazers at Old Trafford - depends on perennial European success. Going out at this stage is a disaster, but not qualifying for next season is unthinkable.

Benitez knows that defeat in Lyon would be the lowest point of his managerial career at Anfield, and plummet his side to depths from which it will be hard to scale the summit of the top four.

Which is why Agger was standing. He will be given every chance of playing tonight, to form a makeshift central defence with Sotirios Kyrgiakos, who was signed for £1million in the summer to act as cover.

That will allow Jamie Carragher to switch to right-back, and youngster Emiliano Insua at left back, to give a makeshift look to a defence that will be severely tested in the Stade de Gerland, a venue in which Lyon average two goals per game in their Champions League adventures.

With Steven Gerrard not travelling, to run Benitez’s injury list into double figures, it is a bleak prospect which could persuade the manager to gamble not only on Torres and Agger, but also on Alberto Aquilani, who has made just one appearance as a substitute for the club since his £20million arrival in the summer.

Yet the Liverpool manager is surprisingly well versed in these desperate situations. Two years ago he needed a miracle to reach the knockout stage, but succeeded in doing that spectacularly with the help of a 4-0 victory in France over Marseille. He will use the spirit of that game to inspire his players.

“We have spoken about that game in Marseille, about the spirit we showed and the performance we produced under very similar circumstances and the good memories we have, and we can do it again,” he said, with just the hint of confidence that every Liverpool fan will relish.