Chelsea striker Diego Costa is reportedly trying to frustrate manager Antonio Conte by forcing the club to delay a move for Everton forward Romelu Lukaku.
Conte is believed to have informed Costa via text message at the end of last season that he is no longer wanted at the club.
The controversial striker scored 20 Premier League goals to help the Blues win the title, but it is understood that he does not factor into the manager's plans for the upcoming campaign.
According to The Mirror, Costa is keen on a return to Atletico Madrid, but he refuses to leave Stamford Bridge unless it is on his terms, which is forcing the club to delay making a move for Lukaku.
The report claims that the Spain international, who has rejected a big-money move to the Chinese Super League, is enjoying the difficulty that Conte is experiencing.
If Costa joins Atletico this summer, he will be unable to play for the club until January 2018 when their transfer ban is lifted.
