Atletico Madrid president Enrique Cerezo admits they must sell if they're to buy in January.
Cerezo concedes they need to keep their books balanced if they want to add to coach Diego Simeone's squad during the winter market.
He said, "We cannot sign, we have to sell someone to sign someone, but we have a fantastic team.
"We cannot sign for the salary limit, unfortunately."
Cerezo also confirmed Diego Costa will need surgery after a herniated disc was discovered: "They're going to have to operate."
