Since the departure of Vincent Kompany three years ago, City manager Guardiola has allowed his squad to elect their own skipper.
The armband was taken by David Silva for the 2019-20 campaign with Fernandinho having taken the role for the past two seasons.
With the veteran Brazilian midfielder having left the Etihad Stadium over the summer, a new leader now needs to be chosen.
As City's most influential player in recent seasons, De Bruyne, 31, would seem a natural choice.
"They are going to take the decision next week," said Guardiola. "I'm pretty sure Kevin will be (chosen).
"As the oldest player here, (with) the responsibility he takes on the pitch, and in many cases off the pitch, he will (have) a key role within the team, I'm pretty sure.
"But I don't pick. They pick. It's not a question of favourites - what the team decide is perfect. What the staff decide I'm happy (with)."
The top five in the vote will form the squad's 'leadership group' - a core of senior players who can all wear the armband when the squad is rotated.
Last season, well as Fernandinho, the group included Ruben Dias, Kyle Walker, Ilkay Gundogan and De Bruyne.
Speaking about their responsibilities, Guardiola said: "They have to defend the team when they don't agree with the manager.
"I love the captains being decided by them, not me. It belongs to them, in the locker room.
"I never vote. The only person who doesn't vote is me. What they decide is perfect, not a problem."
Guardiola, meanwhile, is set to hand star summer signing Erling Haaland his debut as City begin their new season when they face Liverpool in the Community Shield at the King Power Stadium on Saturday.
The prolific Norway striker joined City from Borussia Dortmund in a £51million deal after months of being linked with the club.
Guardiola said of the 22-year-old: "He's ready to play, and the first impression (of him) as a guy is really good, a funny guy. He's settled really well with the team. That is important.
"Apparently people think that's not one of the most important things but the good vibes in the locker room are more important than any advice or any other thing you can say.
"We try to settle good with the family, house, and try to get to know each other in training. We can see what we want to do. The quality will do the rest."