The former Liverpool and Chelsea striker was presented to the fans at the Vicente Calderon Stadium while waiting for his loan from AC Milan to become official when the Italian transfer market opens on Monday.
Torres says he returned to Diego Simone???s Spanish champions in bid to rekindle his competitive spirit with his boyhood club.
The 30-year-old, who left Atletico in 2007 for Liverpool, said: “I was missing something to motivate me, something that I could only find here.
“When I was 24 I understood something that was very hard for me, that I needed to leave so the club could grow and so I could also grow.
“That was the most difficult moment of my career. The club has grown and won important things. I too got the titles I was looking for, but I was missing something. I want to win them here.”
“I have been dreaming for so long that that one day this could be a reality. It is difficult to believe it now.”
Torres scored 65 goals in 102 league games for Liverpool before moving to Chelsea for a British record transfer fee of ??50m in 2011.
However, he struggled to rediscover his goalscoring touch at Stamford Bridge and was sent out on loan to Italy in August but only managed to find the target once in 10 games.
Torres??could make his debut against crosstown rivals Real Madrid in the first leg of their round-of-16 Copa del Rey tie on Wednesday.