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.
Atletico's task against Chivas was made tougher by Marcos Llorente's 24th-minute dismissal, but Trippier was proud of their response.