Chris Gunter will stay at Reading, after the club took up the option to extend his deal by another year.
Kenwyne Jones' loan departure from Cardiff was a 'business' decision, according to Bluebirds boss Russell Slade.
The Turkey international moved to Spain from Galatasaray in 2011, helping Atletico win the Europa League in his first season and the Copa del Rey last term.
The 26-year-old told the club's website: "I feel very happy to have extended my contract with Atletico.
"After two years with Atletico I I feel like part of the family which is the club. If I'm so happy at the club, its because my team-mates are so strong and we're all in this together."