The 29-year-old striker, who signed a four-year deal for a reported fee of €32 million from Sevilla on Saturday, says he likes everything about his new club.
"I'm very happy to be here and play for a big club like Atletico," Gameiro told Marca. "I've spoken to [Diego Simeone] on the phone, and he told me he wanted me and that we'd have a great season.
"I like Atletico's style of play, team and mentality. I think I can achieve many things here this season. I didn't hesitate to come here, everything was clear to me.
"[The atmosphere at the Vicente Calderon] is very hot, [Atleti] have very good fans and I like this."
And commenting on Griezmann, Gameiro added: "He is a great French player like myself and I'm certain we'll score a lot of goals together, although he hasn't called me yet, he's on holiday!"
Gameiro joined Los Rojiblancos from Paris Saint-Germain in 2013 for a fee of €10m and subsequently made 140 appearances in all competitions, netting 67 goals and providing 16 assists.