Atletico Madrid president Enrique Cerezo says Diego Costa must help them if he wants to leave Chelsea.

Cerezo admits they're interest in Costa, though their summer transfer ban means he won't be able to play for Atletico until January.

"He is the one who has to say and make decisions.

"Costa is a Chelsea player and we can not even say we are interested," Cerezo told Cadena Ser.

"What I can say is that we are in a situation where we work for the future (due to transfer ban)."