The Brazil-born striker is expected to depart Chelsea this week after falling out with management at Stamford Bridge, and a return to Atletico is seemingly the expected outcome.
And while the Spanish club have not yet reached an agreement with the Blues, Cerezo insists he will not give up hope of bringing the Spain international back to the club he left in 2014.
“He [Costa] has a contract with another club, it’s a complicated matter,” Cerezo said on Spanish radio station Cadena SER.
“We are taking things with ease. As long as Chelsea do not agree to his transfer, Costa will be [a] Chelsea [player].
“Am I pessimistic or optimistic regarding the arrival of Costa? I am always optimistic.”