City take on the Blades at Wembley on Saturday, with a 16:45 kick-off.
Guardiola this week witnessed first-hand Grealish’s desire to be ready physically for the last four clash as well as the hectic season run-in, which sees us fight on three fronts.
As City arrived back in Manchester from Munich on Thursday, the boss noticed that Grealish headed into the training ground to work on his fitness - rather than make his way home.
He said: “I’m impressed with how professional he is.
“Yesterday we arrived at six and he was here making treatment to prepare, just in case he’s needed.
“He wasn’t used, at Villa, to playing three games a week for a long time.
“He knows his body and regeneration.”
Grealish is really hitting top form in 2022/23 after finding his feet in his debut season in sky blue.
It is not an uncommon occurrence for players to take time to acclimatise to life at City under Guardiola.
But the manager is keen to reiterate the fact that, for Grealish, it was a long lay-off through injury, the season before he joined City, which hampered his progress.
Match preview | City v Sheffield United
The playmaker missed 12 games for the claret and blues due to a shinbone injury, which left him touch and go for that summer’s European Championships and ensured he arrived at the Etihad with less game time than he would have hoped.
The manager added: “We can’t forget Jack, last season, came from Aston Villa in the previous season with six or seven months injured.
“He didn’t have the rhythm he has now. These details can influence a lot.
“Sometimes you need a little bit more time but if the mind is there always you can adapt quickly.
“Always I believe it’s the players when they believe.
“For example Bernardo, I had the feeling from day one he could adapt.
“Players believe I am playing for Manchester City, I am able to play here, they won the Premier League, in their mindset they are ready to play here.
“Of course I am good enough to play here, of course I have the ability.
“Some players just need a little bit more time than other ones.”
