However, Costa was linked with a return to the Spanish club in the summer, and may well have rekindled speculation after sharing a dinner with Simeone.
“Great reunion and great memories,” the 28-year-old wrote, having won La Liga, the Copa del Rey and the UEFA Super Cup during his time in the Spanish capital.
Atletico is currently fourth in La Liga, six points behind Real, while Chelsea is second in the Premier League, a point off Liverpool.
Following the international break Atleti faces Real in a titanic capital derby, while the Blues will square off against Middlesbrough.
