That’s according to Spanish football expert Guillem Balague.

The Spain international is still AWOL, despite being included in Chelsea’s Premier League squad.

Costa is refusing to return to the Blues and won't train under Antonio Conte, with the striker desperate to return to Atletico.

The 28-year-old spent four years in the Spanish capital before joining Chelsea in 2014.

However, Blues boss Conte told the hitman he is no longer in his plans.

The Italian text Costa at the end of last season telling him to find a new club, replacing the striker with Alvaro Morata.

Starsport today reported on Spanish newspaper Marca's claim about Atletico making another Costa bid.

And Balague says Atletico have made a final £48m offer for Costa, but Chelsea want around £57m.

“Atleti have made one last offer. It's €55m (£48m) plus €10m (£8.8m) in bonuses,” Balague told Sky Sports.

“They say it's a final offer but that doesn't mean much at all.

“If Chelsea reject it they will have to find another €10m (£8.8m), which is about the difference in valuation between Chelsea and Atleti at the moment.”