De Bruyne, 33, has also attracted interest from Saudi Arabia and admitted publicly last month that he was open to a move there and was tempted by the "incredible amounts of money" on offer "in what may be the end of my career".
But Guardiola moved to shut down suggestions of De Bruyne leaving when asked about the Belgium midfielder's future on City's pre-season tour of the US, where they are due to play AC Milan on Saturday. "Kevin isn't leaving," the City manager said.
It remains to be seen if an enormous offer was to arrive for De Bruyne whether that situation would change but Guardiola said he expects to be operating with more or less the same squad next season.
"If someone leaves, we're going to talk about that," Guardiola said. "Of course, until the last day, we have chances [to make transfers], I don't rule it out the option to have new players but I think there is an 85, 90 per cent chance we will have the same squad."
United completed the PS33.6 million signing of Brazil winger Savinho from sister club Troyes last week and Guardiola is expecting the 20-year-old, who impressed on loan at Girona last season, to make a big impression.
"The impact he did in Girona was absolutely amazing," Guardiola said. "I think Michel, the manager, has done an absolutely incredible job with him.
"He can play on both sides, left-winger, right-winger, can even play in the middle. But we need [him] more especially on the wings. His one-against-one is devastating. We cannot forget that Savinho is playing national team for Brazil. We don't have many wingers that can play on both sides. He can use two positions."
Borussia Dortmund, meanwhile, remain in talks with City over the potential PS25 million signing of Brazil full-back Yan Couto. Couto joined City from Coritiba in 2020 and has been on loan at Braga and Girona in recent seasons.