Chelsea strike Diego Costa has been unsettled by big money Chinese interest.

The Sun says they face a battle to keep hold of Costa after he was offered a staggering £38m a year to join the Chinese Super League revolution.

Costa, who has 16 Premier League goals this season, is determined to test Chelsea's resolve to keep him in the summer.

They made it clear to the Spain striker that he would not be sold before the Chinese Super League transfer deadline passed last night.

But Costa's head has been turned by the staggering salaries on offer in Chinese football.

Despite accepting that he will have to stay at Chelsea until the end of the season, Costa's future is far from certain.

Chelsea still want to pin him down to a new contract after making it clear that he would not be sold last month.