LONDON (The Guardian) - English Premier League side Liverpool have signed Marko Grujic from Red Star Belgrade for £5.1 million (S$10.7 million).

The 19-year-old Serbian midfielder has signed a four-and-a-half-year deal at Anfield but will be immediately loaned back to Serbia's league leaders for the remainder of the season.

Internazionale and Chelsea were among a host of clubs interested in Grujic, part of the Serbia squad that won the Under-20 World Cup last year, but the playmaker opted for Liverpool following a personal intervention from Juergen Klopp.

The Liverpool manager moved for the first signing of his Anfield reign at the request of his assistant, Grujic's compatriot Zeljko Buvac, and a deal was agreed in principle during talks in Belgrade before Christmas .

Red Star insisted on retaining their academy graduate for the rest of this season's title challenge and attempt to qualify for the Champions League.

The teenager underwent a medical on Merseyside on Monday and is due to return to Liverpool for pre-season training in July.

The Reds have also added another teenager to their ranks in the form of the Polish Under-17 goalkeeper Kamil Grabara.

The highly rated 16-year-old, who turns 17 on Friday, had trials with Manchester United and Manchester City after attracting widespread attention at Ruch Chorzow but has agreed a move to Anfield for an initial £250,000.

Liverpool are also considering their options for a new central defender in January having finished Tuesday's Capital One Cup semi-final win at Stoke City with all of their available, experienced options injured.

Tiago Ilori is expected to return from Aston Villa once his season-long loan deal is cancelled but is not viewed as a long-term solution while Joel Matip, the Schalke defender who is out of contract in the summer, has yet to decide on his future.