The 25-year-old, who has made six appearances this season, produced a fine save from Bruno Fernandes in the 2-0 win at Old Trafford on Wednesday and could make his third start in a row against Birmingham City in the FA Cup on Sunday.
"He's settled perfectly to the dynamic of the group," Guardiola told a news conference on Friday. "He's a guy who listens in training.
"He's been training with maybe the best goalkeeper coach with Xabi [Mancisidor] and he has the opportunity to improve a lot.
"He made an incredible save in the first half from the shot from Bruno Fernandes but they were actions with the ball that he's done really well."
Guardiola is set to hand striker Sergio Aguero his first start since October when Birmingham, 18th in the Championship, visit the Etihad Stadium.
The 32-year-old has only managed nine appearances this season after recovering from a knee injury. Sources have told ESPN Aguero is still waiting to discover whether or not he will be offered a new contract with his existing deal set to expire in the summer.
"He has trained really well," Guardiola added. "Today [Friday] he was off but if tomorrow he feels good he's going to play [against Birmingham].
"It would be great to have him fit and in the best condition, he's optimistic and positive, he's been saying he will do a good season -- "I will score a lot of goals" -- and this is the most important thing.
"We don't want to put him under pressure. There are games that maybe we don't need him but we do for most of the games."