The teenage midfielder has been a big success story for Atletico this season.
After signing to 2028, Barrios said: “It's like fulfilling a dream, that you are already part of a locker room of players and coaching staff that you haven't seen on TV for a long time. It is incredible.
"Now I have to continue working to give my best. Ever since I started playing, you dream about it one day and once you've achieved it, it's 'wow', how strong, you still can't believe it.
“I arrived at Atleti when I was a Cadet and Atleti has given me everything, not only on the pitch, but also in values."