Diego Costa is unlikely to return to Atletico Madrid from Chelsea, according to the Liga club's president Enrique Cerezo.
Costa, who is currently serving a three-match suspension, has been linked with a move back to Atletico over recent weeks amid speculation that he is unsettled at Stamford Bridge.
The Spain international scored 64 times in 133 games for Atletico, helping the club to the 2013-14 La Liga title before joining Chelsea, but Cerezo is not optimistic of a deal being struck with the Premier League side.
"He has a contract with Chelsea," Cerezo told Al Primer Toque Onda Cero. "There are many times when, as much as a I want a player, there is a contract.
"To negotiate with Chelsea can be really tough, almost impossible."
Costa, who was dropped by Spain for their recent international friendlies against Italy and Romania, is at Chelsea alongside another former Atletico fans' favourite in Radamel Falcao.
The Colombia international's loan spells in England from Monaco with Manchester United and Chelsea have failed to take off due to form and fitness woes.
Falcao was an unused substitute for Saturday's 4-0 win over Aston Villa, having scored once in 11 competitive appearances for Chelsea - the last of which came last October.
"Radamel Falcao? He's been injured and we don't know the extent," Cerezo added.
"Nobody has offered Falcao to us. If his agents have been in contact with the club, I don't know about it."