Atletico Madrid striker Diego Costa has reportedly threatened to quit the club in dispute over his wages compared to Antoine Griezmann's.
The Spain international, who currently earns a rumoured £7m a year at the Wanda Metropolitano, has been in early discussions with Atletico over a new contract.
Talks between the player and club are said to have turned bitter, however, as Costa is demanding to be paid the same as strike partner Griezmann, somewhere in the region of £17.5m.
If Atleti do not keep parity, Spanish outlet Marca suggests that the 30-year-old is prepared to force his way out and take advantage of the riches on offer in China.
Costa returned to Atletico from Chelsea in a £32m transfer last year.