The former Sevilla man has revealed that a return to Spain would interest him after labelling los Rojiblancos a "great club"
The 25-year-old joined the Portuguese giants in 2011 after spending the previous seven years with Sevilla, but has been linked with a return to Spain with Diego Simeone's men.
Leoes endured a disappointing 2012/13 Primeira Liga campaign, in which they finished in a lowly seventh position, and with rumours gathering over the 25-year-old's future, Capel has done little to dampen speculation.
"It always makes you proud when you are linked to such great clubs as Atletico," Capel told AS.
"I always want to continue growing and that is a great club. Now I do not know what will happen in the future, but any player would like to play there."
Last season Capel made 19 appearances for Sporting, scoring six goals in the process. He has been capped twice by Spain.