Rafael Benitez has warned Benfica they will be wasting their time attempting to wind up Fernando Torres this evening - as Alberto Aquilani's season of injury woe continued.

Liverpool face a thorough examination of their European credentials when they step out at the Estadio da Luz for their Europa League quarter-final first leg in Lisbon.

The in-form Torres took his tally to 20 for the season and seven in his last four games with a superb brace in Sunday's 3-0 win over Sunderland.

The striker also managed to avoid a booking for only the third time in eight matches having grown frustrated at Liverpool's largely underwhelming season.

Torres picked up a yellow card in both legs against Lille in the previous Europa League round, meaning a caution tonight would rule him out of next Thursday's Anfield return.

But Benitez is confident the Spain international will not be affected by any intimidatory tactics from the Benfica defence.

"We have spoken about this in the past," said the Liverpool manager. "Fernando has experience and he knows what to do. For me, the main difference against Sunderland was that he was on fire from the first minute and you could see he was really enjoying his football.

"I'm not worried about him picking up a booking tomorrow night. He has experience, he is confident, and he should be okay."

Liverpool flew to Portugal yesterday afternoon without Aquilani, whose bad luck with injuries continued when he suffered an ankle injury during the morning's training session.

It is the same ankle that delayed the Italian's debut following his summer arrival from Roma, and Benitez refuses to take any chances over the midfielder's fitness.

"He will not be available for this game," said the Anfield manager. "He had a problem with his ankle this morning and we have to fix it.

"It doesn't seem too serious but it's the same ankle as before and so we'll have to analyse the situation carefully."

The Europa League represents Liverpool's final chance this campaign of ending a silverware drought that stretches back to the FA Cup triumph in 2006.

But Benitez refuses to look beyond tonight's game, and said: "The main thing for everyone at a football club is to have the option to win trophies.

"Not just for the players, but for the fans and the staff as well.

"The Europa League is an opportunity for us and I am sure all the players here see the competition as a way to change this season around. But I don't want to talk about winning the Europa League now. First we have too beat Benfica, and next will be either Atletico Madrid or Valencia so it will be very difficult. There is a long way to go."

Indeed, Liverpool could not have been handed a more difficult route to the final in Hamburg on May 12, with Benitez asserting the standard of teams remaining in the competition rivals that of the Champions League.

The Liverpool manager said: "Maybe there is a difference at the start of the competitions but when you see the names of the teams who are left in the Europa League at this stage, it is very strong. It is important for players to face the good teams in Europe, it gives them an extra motivation. Benfica will be very tough, Atletico Madrid have quality, as we saw in pre-season, and Valencia are doing well in the league. It will be very difficult for us."

With Maxi Rodriguez cup-tied, Lucas Leiva and Yossi Benayoun are both pressing for a recall to the starting line-up.

Meanwhile, Martin Kelly underwent knee surgery yesterday which will rule him out of action for the rest of the season.

This story has been reproduced from today's media. It does not necessarily represent the position of Liverpool Football Club.