Maddison had been out since November with an ankle injury but the midfielder has now returned to training and is in line to make his comeback in the fourth round showdown on Friday night.
"Team news, everyone’s ok from the last game. Deki’s [Dejan Kulusevski] recovered from his illness," Postecoglou said.
"The boys had four days off last week, which was good for them.
"Post-that, Madders has been training with us, he’s had a full training week. He’s in a good place. Ben [Davies] and Dane Scarlett have just started back with the group as well. So we’re getting the numbers back up.
"I think the ones who are definitely still out are Gio [Lo Celso], Manor [Solomon] and Alejo [Veliz] - they’re the ones still away from the group."
Asked if Maddison is ready to start, Postecoglou added: "He's trained all week and he is fine. He is available so when someone is available I assume they are ready to start.
"Whether they do or not depends on what I see with everyone else tomorrow and I usually make those decisions [on] game day. Like I said, the beauty of it is he's got through the week really well and is ready to go.
"You take all those things into account, whether they can come straight back into the team or whether they need another week, how are we in those positions, how are we placed in terms of the health and fitness of the other guys.
"The positive for me is that he's available and that gives us more options with the starting lineup. but even with the ability to change a game because if he starts then somebody who has been playing regularly doesn't but it means they can make an impact. We're probably one of the few teams that hasn't had a massive impact with our substitutes during this period.
"Early in the season we were good because we had a stronger bench. We've just been really limited in those attacking midfield positions so it gives us more options."
Maddison was one of the most influential players in the Premier League before his injury against Chelsea at the start of November and Spurs will hope he can play a key role in the second half of the season.
His return will boost Postecoglou’s attacking options, with Spurs again without captain Heung-min Son against City.
He remains at the Asian Cup with South Korea, while midfielders Yves Bissouma and Pape Matar Sarr are still away at the Africa Cup of Nations with Mali and Senegal respectively.