The England full back came on as a late substitute and was deployed in goal after Claudio Bravo - who himself had come on as a half time substitute for Ederson – was sent off.
Guardiola explained afterwards, “Xabier Mancisidor, our goalkeeping coach, suggested Kyle for his courage, and we were lucky to only concede one shot.
"Congratulations for the courage and desire to help the team.
“Everyone knows how difficult it is to play Atalanta so the fact that we have taken four points off them is a big success for us particularly with the injuries and difficulties.
“We played well in the first half and then dug deep in the second."
He added: “It is a good result away against a good side and we need one more point to win the group and hopefully against Shakhtar Donetsk at home we can do that."