Atletico Madrid coach Quique Sanchez Flores has opened the door to Sergio Aguero's sale this summer.
Manchester United, Manchester City and Chelsea are all being linked with the Argentina international, who has little over 12 months to run on his existing deal.
"He's a special player and, as such, there is always the possibility that the club may lose him," said Flores. "I've always thought that there are many ways to work this team with or without him.
"The fans, in that sense, should be calm."