Reports suggested Jose Mourinho had secured the services of the £32m-rated Costa on a five-year contract following Chelsea's Champions League exit to Atletico where the Spanish international was on target in the return-leg at Stamford Bridge.
"Chelsea? We do not know when these [remaining] games are so important," Cerezo told El Mundo Deportivo.
"We do not want to destabilize the team and we can talk about this later. I can say that there is something, not officially, from another club regarding any of our players.
"They are not heading to any other team.
"If the question is 'Is there an agreement for Costa?' then we have not heard anything."
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