The left-back played just 27 matches in his first two seasons at the Club due to two serious knee injuries.
But he returned to action in September and has played 19 times this term.
Having been eased in initially, he has seen his game time increase in recent weeks, with his performances steadily improving
BUY: Tickets to see City take on Real Madrid in the Champions League
READ: Which TV channel is Sheffield United v City on
And Guardiola says he has been impressed with what he’s seen.
“Yeah, today he played really good,” the City boss declared.
“His decisions in final third were good. He played a good game, put in good crosses.
“He plays after two seasons injured, so his physical condition is getting better.
“The game demanded the crosses. The intention was to get people in the box.
“In the end the crosses were well delivered, especially on the left with Mendy.”
Meanwhile, Guardiola says he doesn’t now if Aymeric Laporte will be fit for next weekend’s FA Cup fourth-round tie at home to Fulham.
The French defender returned to training earlier this month having damaged his cartilage and lateral meniscus during our win over Brighton back in August.
Guardiola says he is being assessed by Club doctors, but insists Laporte will need time to rediscover his best form after a lengthy absence.
“We cannot expect Aymeric to solve all the problems,” he said. “It has to be everyone.
“He is getting better. Tomorrow [Sunday] the doctor will evaluate him. But after four, five months he will need time.”