Haaland, who has scored 22 goals in 16 games in all competitions for City this season, was replaced by midfielder Bernardo Silva in the second half of their 0-0 draw with Borussia Dortmund in the Champions League on Tuesday.
"He feels better but we will train this afternoon and we will assess in a few hours," Guardiola told reporters on Friday.
"We will see how he is feeling and then we will decide."
Guardiola said City's Argentina forward Julian Alvarez will be the first option to replace Haaland if the Norwegian is not fit for Saturday's game.
Unlike the impressive Haaland, Alvarez has scored only two league goals this season but Guardiola was not concerned with the numbers given the Argentine's limited playing time.
"Play 90 minutes every game and he will score goals, maybe not like Erling, but he will score goals," Guardiola said. "I don't judge.
"I know how many minutes he plays and how difficult it is when you are not used to playing regularly ... since day one, we are really impressed with many things about him."
Goalkeeper Ederson will return to the squad for Saturday's game after being rested, while Guardiola said England duo Kyle Walker (shoulder) and Kalvin Phillips (groin) are "getting better" as they aim to recover before the World Cup.
"They are positive and optimistic. They're in touch with (England manager) Gareth (Southgate). I don't know, hopefully they can be ready to be selected (for the World Cup)," Guardiola said. Southgate is expected to name his squad on Thursday,
"He (Phillips) feels really well, his mobility in his shoulder is perfect. He has to avoid contact with his team mates at the moment. If he is fit and I believe he can play then maybe he can make some minutes (before the World Cup)."
City are second in the league with 26 points after 11 games, two points behind leaders Arsenal, while Leicester are 17th with 11 points from 12 games.
