5 of the best free transfers of the January window 

#3 Lassana Diarra (PSG)

The 32-year-old could prove to be a key signing in midfield for Emery

Former Chelsea, Arsenal and Real Madrid superstar, Lassana Diarra has been signed by PSG on a free transfer until the end of next season. The veteran central midfielder has played in some of the biggest leagues and games over the last decade and is a promising signing for PSG.

PSG have captured a superb player with a good temperament who is capable of playing at the highest level of the game. Diarra has also been capped by the French national team on 34 occasions and remains an outside contender for a spot in the French WC squad.

A skilful central player with superb game reading ability, Diarra also possess a very good passing range as well as a strong physical presence in tight areas. He could prove to be the missing link with the know-how of to handle the occasion for PSG's during their UEFA Champions League early knockout phase run-in this season.

He will add stability to Unai Emery's team in the middle of the park and will prove to be an impressive signing for the club on and off the field. With the number of stars at the club, a figure like Diarra could be vital for youngsters at the club while they grow into mature footballers.