The 28-year-old made his debut for La Roja last month, starting and playing 58 minutes in a 1-0 friendly loss against France.
Garcia told Marca: "I've played in a number of positions for Atleti and I'm glad [Vicente del Bosque] feels he can turn to me to fill in when there's someone missing or he needs someone to do a specific job.
"There's a reason I'm here. It's not a handout - I've been around for a long time. It's an honour to be here and I'm going to keep plugging away to get another call-up."
Garcia has been on the Vicente Calderon outfit's books since 2007.