© Getty Images Enlarge Daniel Agger was named vice-captain before the start of the season

Napoli have made a bid to sign Liverpool central defender Daniel Agger on loan in January.

Rafa Benitez, the manager who brought the 29-year-old to Anfield from Brondby in 2006, is looking to take him to Serie A.

Representatives from Napoli contacted Liverpool on Monday to enquire about the possibility of a deal, sources told ESPN.

Liverpool are expected to reject the approach, having rebuffed Manchester City's interest in the summer of 2012 and then turned down a £14.6 million bid from Barcelona in August this year.

Agger was named vice-captain at Anfield before the start of this season, replacing Jamie Carragher, who retired in May.

But the Denmark international has been in and out of the side - partly because of injury and illness, but also as a result of changes in formation and personnel imposed as manager Brendan Rodgers seeks his most successful defensive combination.

Agger started the campaign alongside first Kolo Toure, then Martin Skrtel, but was forced to drop out after suffering a rib injury in a freak gymnasium accident the day before a 2-2 draw at Swansea on September 16.

He returned for the 1-0 defeat against Southampton five days later, but was not fully fit and was unable to complete the match.

In the meantime, Rodgers switched from a flat back four to a three-man central defence, and Agger was unable initially to force his way back in when fit again.

He had to wait until November 9 for his next start, in a 4-0 win over Fulham, as Rodgers returned to a back four.

But Agger has been in and out of the side since then, with Mamadou Sakho selected ahead of him to play alongside Martin Skrtel in Sunday's 5-0 win at Tottenham.

Benitez, who managed Liverpool between 2004 and 2010, took charge at Napoli in May after six months as interim boss at Chelsea.

He brought in Liverpool goalkeeper Pepe Reina on a season's loan in July, and also attempted to sign Reds centre-back Martin Skrtel during the summer.

Agger said in November that he found being out of Liverpool's first team frustrating, but wanted to fight for his place.

He said at the time: "It is difficult to describe but I want to play all the time, every single game.

"When you are not playing, that is difficult. But while that is sad, I just try to work even harder every single day in training - not complaining, just doing everything a bit extra.

"I am more than capable of being in the team - I feel I belong there - but it is the manager's decision and sometimes that is difficult to change in training.

"You need to grab the chance when it is there - that is what football is all about.

"I know I am here and as long as I am doing everything I can to be in that team, and I feel I am good enough and the manager can use me, then I'll be here."

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