Liverpool are believed to be interested in Schalke 04 defender Kyriakos Papadopoulos. The Liverpool Echo believes the Reds could launch a summer bid for the Greek international, who will be expected to replace 35-year-old Anfield veteran Jamie Carragher. The ex-English international will retire from professional football at the end of the season.

The Echo's report references comments by Tor-Kristian Karlsen, president and former sporting director of Ligue 2 club AS Monaco. The Norwegian tweeted on Thursday, posting: "Liverpool interest is concrete. Has been on the shortlist/highly rated by many European top clubs (incl. Chelsea, Man City, Man Utd). Nice transfer coup for Liverpool if they manage to land Kyriakos Papadopoulos (centre back, born 92, Schalke 04, Greece national team)."

Kyriakos Papadopoulos

The 21-year-old Papadopoulos is sidelined with a knee problem and will not play again before next season. The centre-back is contracted to Schalke till 2016 and has managed nine Bundesliga starts this term, with one goal to his name.

Last seaosn, the Greek was an integral part of the club's Europa League and domestic run, scoring four times in 40 starts in the two competitions and helping the side to third in the table.

Karlsen also tweeted: "However, has been ruled out since late November from a knee injury. Expected to resume training in time for pre season. Before the injury I certainly rated him as one of the top centre-backs in European football, hopefully he'll return to same physical shape."

However, Liverpool and Brendan Rodgers will face competition for Papadopoulos' signature, with the Metro believing Chelsea, Atletico Madrid and Manchester City are all interested in the Greek. At the time, the defender was valued at £15m, which makes him an expensive proposition for the Reds, particularly since it seems Rodgers will have no more than £20m to spend in the summer.

Sir Alex Ferguson Hails Carragher

Jamie Carragher

Retiring Manchester United boss Sir Alex Ferguson has praised Carragher as an integral part of Liverpool's defences. The Scot told the Merseyside club they were "lucky" to have held on to him for over a decade.

"He's absolutely a player I admire. He's the epitome of a loyal, dedicated player who Liverpool have been lucky to have for more than a decade. He's been a bedrock of their defensive qualities for years and years. I loved him. He's a fantastic example for any young lad that wants to play the game. He's been a really, really good professional," Ferguson stressed.

"I used to rave about Brucie [Steve Bruce] and the nine years he had with us, and I think Jamie Carragher is that exact same mould - can play with injuries, gets knocked about and gets back up, hardly misses a game," the Scot concluded.