Chelsea striker Diego Costa has deleted his Instagram profile leaving his club unaware of his whereabouts, according to the Sun.
The Premier League champions were believed to be keeping tabs on the disillusioned striker after he refused to return to London ahead of the start of the new season.
Now they are reportedly not clear as to where Costa is, despite suggestions that he could be set to return to the team having been included in their Premier League squad.
The Spanish forward attempted to instigate a move to Atletico Madrid before the close of the transfer window, but the deal failed to materialise and he is now likely to be forced to wait until January.
Costa was informed by manager Antonio Conte via text that he was not set to be in the club's plans for the coming season.
The 28-year-old is in his hometown, Lagarto, in Brazil and is being fined £300,000 for every two weeks of his absence.
Atletico are believed to still be hopeful that a deal with Chelsea can be completed despite the issue of the £50m asking price.
The Spanish club are unable to play new signings until January due to their FIFA-imposed transfer ban, and Costa would have been sent out on loan had he returned to his former club this summer.
Costa claimed earlier this month that he had been treated like a "criminal" by Chelsea in the transfer saga.
“My desire is to go to Atletico (where he played from 2010-14). I’ve spoken to Chelsea director Marina Granovskaia. I said, ‘If the manager doesn’t want me, I want to go to Atletico Madrid’.
“They want me to be there training with the reserves. I wouldn’t be allowed access to the first-team dressing room and I would have no contact at all with the guys. I’m not a criminal! I don’t think it is fair after all I have done to be treated like that.”