Chelsea owner Roman Abramovich remains furious with their FA Cup humiliation at Barnsley on Saturday.
One of Abramovich's close advisors told The Sun that "Grant had blown it" in reference to the prospect of him keeping his job beyond the end of the current campaign in May.
The Russian billionaire was willing to accept the Carling Cup loss was just a bad day at the office.
But the shock 1-0 defeat against Barnsley in the FA Cup quarter-final was the Blues' worst result since he bought the club in the summer of 2003.