New ankle problem for Aquilani

Aquilani has been beset by injury problems (GETTY IMAGES)

Liverpool midfielder Alberto Aquilani has been ruled out of tomorrow's Europa League quarter-final first leg clash with Benfica.

The Italy international sustained an ankle injury in training this morning and will not fly out with the squad to Lisbon later today.

"He will not be available for this game," said manager Rafael Benitez.

"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."

Aquilani arrived in the summer after a £17million move from Roma with an ankle injury which had ruled him out of the latter stages of the 2008-09 Serie A season.

It took a while for him to regain match fitness and, as a result, he has made just eight starts and 11 substitute appearances this season.

Benitez also confirmed defender Martin Kelly will undergo a knee operation today which will rule him out of action for the rest of the season.

The 19-year-old defender tore the meniscus - a similar problem to the one which resulted in striker Fernando Torres having surgery in January which sidelined him for five weeks - in training on Saturday.