Barcelona Transfer News: Latest Kalidou Koulibaly and Javier Mascherano Rumours

Barcelona reportedly want to bring Napoli defender Kalidou Koulibaly to the Camp Nou next summer, while Javier Mascherano may not be allowed to leave in January due to Samuel Umtiti's injury.

The Catalan giants are set to make a move for Koulibaly at the end of the season, but he could cost up to €60 million, according to Il Mattino (h/t Football Italia).

Premier League sides Chelsea, Arsenal, Manchester City and Liverpool have all shown an interest in the 26-year-old, while Napoli coach Maurizio Sarri is hoping to keep the Senegal international at the club.

Koulibaly is one of the best centre-backs in Serie A, according to football pundit Mina Rzouki:

The defender is strong, a good reader of the game but also excellent in possession. 

WhoScored.com illustrated just how effective he can be with the ball:

Koulibaly has helped Napoli to the top of the Serie A table, although it has been a different story in the UEFA Champions League where the club have underwhelmed with six points from five games.

The defender was wanted by Chelsea last summer who offered €60 million, but Napoli refused to sell to the Blues, per La Gazzetta dello Sport (h/t Sport Witness).

It seems as though he may well be in demand again next summer, but luring him away from the Serie A side looks a difficult task.

Meanwhile, Barcelona are set to lose Mascherano next summer but may prevent him from moving in January, according to Catalunya Radio (h/t Sport).

The Argentinian had been considering an offer from China and was also contemplating leaving in order to play more regularly ahead of FIFA World Cup 2018.

However, Ernesto Valverde's side were dealt a huge blow on Saturday after Samuel Umtiti picked up a hamstring injury that will rule him out for eight weeks.

The club confirmed the news via their official Twitter account:

Football writer Sid Lowe highlighted just how bad the news is for Barca:

Umtiti's injury leaves Valverde with just Mascherano, Gerard Pique and the injury-prone Thomas Vermaelen as available senior centre-backs.

Mascherano is currently out injured but is expected back in mid-December, according to the official Barcelona website.

When he does return, he will be needed to partner Pique, with Vermaelen very much fourth choice at the Camp Nou.

That does mean Mascherano will become a key figure again for the club while Umtiti recovers from his injury.

Valverde could call up David Costas from Barcelona B as cover, but Mascherano's experience will be vital, particularly with a Clasico against Real Madrid to come on Saturday, December 23.