The Norwegian striker missed last Saturday’s 1-0 Premier League win away at Leeds United after having picked up a knock in training.
O’Reilly meanwhile was forced off with an ankle problem midway through the second half of the Elland Road clash.
But addressing the media at Tuesday’s pre-match press conference, the City boss said he would take a decision on the pair after Tuesday’s training session
“Erling feels much better but yesterday we didn’t train and now we have training and will decide today,” Pep revealed.
“It’s the same with Nico. We will decide after training.”
City will go into Wednesday’s Etihad clash on a back of a fine run of form.
Guardiola’s side are unbeaten in nine games across all competitions and have won our last six in succession.
It means the Blues are still fighting for silverware on all four fronts as we enter the decisive final three months of the season.
But from Guardiola’s perspective, the focus and message is all about the here and now and training our sights on a Forest side battling to preserve their top-flight status.
And the boss said he had huge respect for the work undertaken by recently appointed boss Vítor Pereira.
“I remember from Wolves [when he was in charge there for the first game of the season], first half I would say they outplayed us and they were much better.
“We were incredibly lucky. He’s a top-class manager.
“I saw the Brighton and Liverpool games and they were alive and always I had the feeling [they were tough] when we play there with Sean Dyche.
“Top players like Morgan Gibbs-White, Callum Hudson-Odoi, Elliot Anderson...
“They have a bigger squad and more in-depth squad with top class players.
“They play for important things like us. We are in most important stage of the season. The last 10 games now start to be decisive.
“Two Premier League games before the international break - we are five behind Arsenal so we can’t drop points.”
Be at City v Nottingham Forest!
We welcome Forest to the Etihad Stadium at 19:30 (UK) on Wednesday 4 March.
And you can be there to see it as Pep Guardiola’s City continue to chase Premier League glory.
Tickets for this game are now on sale to all fans, starting from just £25 for adults and £23 for U18s.
Or, if you fancy something more special, hospitality packages start from just £199 with other experiences tailored for every budget!
