Pep Guardiola praised Sergio Aguero's response after missing two penalties in Manchester City's 5-0 win over Steaua Bucharest on Tuesday.
Aguero twice suffered frustration from the spot inside the first 20 minutes of the first leg of City's Champions League play-off in Romania - but recovered to score a hat-trick in a one-sided contest.
David Silva and Nolito were also on target as City's winning start to the season under Guardiola gathered momentum with an impressive display.
Guardiola said: "The fact he missed the penalties is part of the game but it was important that Sergio stayed focused and didn't get down. He focused on his game and after he scored three goals.
"It's not important how many times you fall down, it's how many times you stand up and try again."
Aguero has now missed four of his last five penalties in European competition.
But asked if the Argentinian will remain as City's first-choice penalty-taker, Guardiola said: "I'm confident if he's confident. It depends on the players. If he's confident, for me it's not a problem."
The emphatic victory all but secured City's place in the group stage of the Champions League for a sixth successive season.
"We are very pleased about the way we played," said Guardiola. "Of course, with the result we are almost in the Champions League. We played really good and so we are so happy.
"Trainers are always happy to win the games but especially the way we played. Eleven players ran a lot without the ball, with the ball they played amazing and we scored a lot of goals."
Guardiola left England goalkeeper Joe Hart on the bench for a second successive game.
Speculation over the 29-year-old's future at the club is increasing and City continue to be linked with other goalkeepers, the latest being Barcelona's Claudio Bravo.
Guardiola was unwilling to discuss the matter.
He said: "I have spoken many times about that. It is the same situation. I decided today the best players for the game."