Haaland has dealt City an injury scare after coming off against Borussia Dortmund in midweek, and was pictured limping following the game.
The 22-year-old, who has a remarkable 17 Premier League goals this season, is "better" according to his manager but will need to come through training on Friday afternoon before a decision is made on the Premier League game.
Guardiola said: "We have training this afternoon and we'll assess in a few hours. We'll see how he feels, if he's fit and after we'll decide. I will know it in two hours if he is able to play or not."
Should Haaland not feature, or start on the bench, Guardiola confirmed that fellow summer signing Julian Alvarez will start.
Guardiola added: "If Haaland doesn’t play then Alvarez is the natural first option to replace him."
Elsewhere, Joao Cancelo is hoping of shaking off an illness to play, while Phil Foden will be pushing to start after coming on as a substitute against Brighton.
Predicted Manchester City XI: Ederson; Cancelo, Dias, Akanji, Laporte; Silva, Rodri, De Bruyne; Foden, Haaland, Grealish.
Injured: Walker, Phillips
Doubts: Haaland, Cancelo