The veteran keeper came off the bench for Ederson on 73 minutes and moments late made an excellent save to deny Paulinho as City drew 0-0 with Sporting.
Carson’s appearance was his first in the Champions League since April 2006 when he played for Liverpool against Juventus – the longest gap in the competition’s history.
“We are delighted,” said Pep.
“He is very important to us behind the scenes.
“People listen when he speaks. He made the biggest save (of the game).”
Watch Pep’s full post-match press conference on the video above…