He has started only 19 games this term, including seven in the Premier League.

"He is the same player, he has the same manager, and the way we play has not changed," said Guardiola.

"It's just the way he has performed. That's the difference."

This season, Grealish has had limited top-flight minutes and of his 19 starts, four were in the Community Shield, the European Super Cup, and both ties at the Club World Cup in Saudi Arabia.

He last started a league game on 30 December against Sheffield United, when he was replaced by youngster Oscar Bobb after 52 minutes.

The £100m man remained on the bench throughout the win at Bournemouth on Saturday and there are no guarantees he will start the FA Cup fifth-round tie at Luton.

"I said from day one, we need him," said Guardiola. "He has a special quality for our team. But it depends on him. Hopefully he can do a good last three months."

Grealish is not the first player to find himself in and out of Guardiola's team, such are the demands the former Barcelona and Bayern Munich coach places on his players.

And the England international has been warned he will not be given time to ease himself back into the City side.

"I cannot give players three or four games to get their rhythm," added Guardiola. "They have to find the rhythm to play for 20 minutes or 90.

"At a high level, the team don't wait to be fit. You cannot give someone three or four games to be fit. What about the 10 who don't play? They deserve not to play?

"You have to see the training sessions and all the small details. The players don't have to convince me. They have to convince themselves that they deserve to play."