Kieran Trippier praised Atletico Madrid's "unbelievable" mentality after making his second appearance for the club following his transfer from Tottenham.
The right-back featured in Diego Simeone's starting line-up as Atletico beat Chivas on penalties after a goalless draw in the International Champions Cup in Texas on Tuesday.
Trippier spent four seasons at Tottenham and helped the club reach the 2018-19 Champions League final before making a reported €22 million ($25m, £20m) switch to Wanda Metropolitano.
SIGN UP with DAZN to watch the Champions League, Premier League, Serie A and more in 2019-20
Atletico's task against Chivas was made tougher by Marcos Llorente's 24th-minute dismissal, but Trippier was proud of their response.
"I thought we reacted well," said Trippier. "The mentality of the team was unbelievable, we continued to press and try to win the ball back quickly.
"We want to win, no matter who we play. That's the mindset from this team and this coach.
"Two wins from two games and long may it continue."
extremely proud to be here and willing to give it my all. The supporters have been incredible. I’ll do my best for the shirt.”
— Atlético de Madrid (@atletienglish) July 24, 2019
FULL STORY https://t.co/Oj87pFX4CX#AúpaAtleti #AtletiSummerTour #ICC2019 pic.twitter.com/pBbtSdA6LL
He added: "I'm extremely proud to be here and willing to give it my all.
"The supporters have been incredible. They've been so nice to me and welcomed me with open arms.
"I'll do my best for the shirt."
Trippier could make his competitive debut for Atletico on August 18, as Simeone's side kick off their latest La Liga campaign at home to Getafe.
Los Rojiblancos finished runners up behind Barcelona last term, while also failing to land a single piece of major silverware across all competitions.
In addition to Tripper, Atletico have brought in eight new players this summer, including record signing Joao Felix and Mexican midfielder Hector Herrera.
Meanwhile, the likes of Antoine Griezmann, Rodri and Lucas Hernandez have all left the club, as Simeone continues to restructure his squad at Wanda Metropolitano.