Antonio Conte to check on Diego Costa's fitness on Tuesday

Diego Costa's fitness will be evaluated by Antonio Conte and his staff when Chelsea's first-team squad return to training on Tuesday.

Costa, who has been linked with a mega money move to China, trained alone on Sunday and Monday as his team-mates enjoyed two days off.

Chelsea say the solitary sessions were part of his recuperation from a back injury and not related to speculation over his future.

Conte has refused to comment publicly on a rumoured falling out and insisted Costa's absence from last Saturday's win over Leicester was due to the back injury which prevented him from training for three days.

The Chelsea head coach also said if there were any issues with players, he would resolve them behind closed doors.

Conte said on Saturday: "If there is a problem - and I repeat 'if' - with the players then in my career I prefer to sort the problem in the changing room, not outside and not in press conference."

Costa, who has scored 14 Premier League goals in 19 appearances this season, will be assessed again on Tuesday to determine if or when he can rejoin first-team squad training.

Earlier this month Costa was linked with a move to the Chinese Super League, with the accompanying astronomical wages. And on Monday several national newspapers reported Costa had rejected a contract extension on improved wages at Chelsea.

It was rumoured Tianjin Quanjian were prepared to bid £80million and Costa's future could be the main talking point of the winter transfer window, which closes on January 31.

One potential complication is that China's transfer window is open until February 28.

Although regulations over the recruitment and use of foreign players have been tightened in the Chinese Super League ahead of the season start in March, it is rumoured that Tianjin have an available slot in their squad.

Costa signed a five-year deal on his arrival from Atletico Madrid in July 2014 for £32m, so has two and a half years to run.

Chelsea and owner Roman Abramovich would resist Costa agitating for a move, with many pundits insisting the striker is integral to Chelsea's push for the title.

Chelsea, who have a seven-point lead at the top of the Premier League, next play at home to Hull on Sunday.