"Julian, I see him doing very well," Romero told reporters at his presentation after joining from Premier League side Tottenham on a five-year deal for 40 million euros.
"I've been here for five or six days, and I see him as always, a guy who wants to keep scoring goals, keep entertaining people, and I see him really focused."
Amid transfer bids from Barcelona and Real Madrid, Alvarez said this summer it would be best for everyone if he was allowed to depart. However, Atletico Madrid held firm and kept the former Manchester City striker.
Neither Romero nor Alvarez, runners-up in the World Cup, were involved in the team's 2-0 win over Malaga on Wednesday, their LaLiga opener.
Coach Diego Simeone said he would try to build the team around Alvarez, while highlighting the "leadership" of Romero, who won the World Cup with Argentina in 2022.
"(Simeone) asked me to be a leader on the pitch, to help my teammates," said Romero.
"I hope to be up to the challenge and carve my name into the history of this great club."
LaLiga
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