The 32-year-old former Barcelona superstar has pledged to give his all for his new side, and took time out to thank club president Alexandre Kalil for bringing him to the Galo.
"When someone receives a lot of criticism, he starts to want to answer those questions and I want to do that,” he told reporters.
“The president here saw a good thing in me and invited me to come here, to give my best to try to win the national title.
"The most important thing coming here was the trust of the president. I want to change my life being here.
"I'm really happy to be here and be able to see the amazing structure that this club has got. I'm trying to do my best for the city. One of the reasons to come here was the energy of supporters. My dream has been always to play in great clubs, this is a good opportunity and I want to give my best.
"The only thing I want to say is thanks to everybody for bringing me here, and thanks for the warm reception. I don't want to speak too much, I want to start playing really quickly. I want to bring Atletico happiness."
Atletico Mineiro currently sit second in the Brazilian championship, having picked up 10 points from their first four games.