Cape Town - Atletico Madrid president Enrique Cerezo would welcome Diego Costa back at the club with open arms, but concedes that re-signing him from Chelsea is a difficult proposition.
The 27-year-old striker won the Premier League title in his first season with Chelsea, scoring 20 goals in just 26 games following his move from Atletico in July 2014.
However, Costa has courted controversy during his time at Stamford Bridge, landing numerous violent conduct charges from the Football Association, while he is currently serving a three-match ban relating to his first red card for the Blues last month.
The Spain international has often been linked with a return to the Vicente Calderon, where he won La Liga and Copa del Rey titles, but Cerezo believes the west Londoners will make any negotiations tough for their Spanish counterparts.
"[Costa] has a contract with Chelsea," he told the Al Primer Toque radio show. "Often, no matter how much you want a player, there is a contract.
"To negotiate with Chelsea can be really difficult, almost impossible."