The Argentina defender has revealed he had no second thoughts about a move to the Madrid-based club and has praised coach Diego Simeone
The 24-year-old has joined the Madrid-based club for a fee believed to be in the region of €3.5m, with the former Liverpool defender unveiled to media on Tuesday following the successful completion of a medical.
“I did not think twice about it, nor have any doubts like it was suggested, I decided straight away to negotiate with Atletico Madrid," he told reporters.
"It is a dream I have had since I was a child, it is a dream of every player to be in this team.
"[Sporting director Jose Luis] Caminero called me directly. When I got the call I could not believe it."
The former Galatasaray player also spoke of his excitement of working with Argentina legend - and Atleti boss - Diego Simeone ahead of his proposed debut at the weekend.
"Will I play this weekend? I’m fit, I’m looking forward and I have much ambition to start work as soon as possible.
"I am unable to say if the coach will pick me. It is up to him.
"Simeone is a great coach. He was a great player and now he is proving how great he is at coaching too and I am thrilled that I can work under him, to continue to learn."