De Bruyne, Grealish ready for City's FA Cup showdown with United
De Bruyne, Grealish, Ruben Dias and Manuel Akanji all missed City's last Premier League game of the season at Brentford last week.
But City boss Guardiola revealed on Friday that the quartet have returned to training and are expected to be involved in the first all-Manchester FA Cup final at Wembley.
"They've trained well in the last two training sessions. They are all of them, more or less, fine," he said.
Guardiola has also confirmed Stefan Ortega will start in goal against United instead of regular first choice keeper Ederson.
Ortega, who started two of City's last three league games, has not conceded a goal in the FA Cup this season.
It is a bold move from Guardiola, whose side are two wins away from becoming only the second English club -- after United in 1999 -- to win the Premier League, FA Cup and Champions League in the same season.
"Stefan is going to play. I have always been like that in the FA Cup. The keeper who has played in the FA Cup is going to play in the FA Cup final," Guardiola said.
Although City surged to the title with a blistering run of 12 successive league victories and finished 14 points ahead of United, Guardiola has no intention of underestimating Erik ten Hag's team.
United beat City 2-1 in January, avenging their 6-3 loss earlier in the campaign, and also ended their six-year trophy drought by lifting the League Cup in February.
Guardiola has been impressed Ten Hag's work in his first season at Old Trafford.
"I look at a manager on how his team improve. When you see a team better and better, in a league that is not easy, you identify a really good manager," he said.
"He represents our profession in the best way possible. I can't say we are friends, we are not in touch much, but I think United have an exceptional manager for many, many years."
If City beat United, they can complete the treble in the Champions League final against Inter Milan in Istanbul on June 10.
But Guardiola urged his players not to look ahead to their bid for a first Champions League crown.
"Thinking about titles, the second or third, we have to analyse the strength of our opponent, look at the weaknesses they have," he said.
"Everything surrounding is normal, you cannot control it. It's special for itself but the question what United have done for the past five months means they are a completely different team.
"They were better when we lost but we played good. I have the feeling that they have improved, the playing patterns are more clear.
"We've done really, really well against them during my time but it's United, the quality of player has always been there."