Spurs’ injury-ridden campaign has left them languishing in 14th place in the Premier League table.
Keane suggested Maddison’s absence isn’t a huge loss for Ange Postecoglou’s side despite fans hoping for his return.
Keane said on Stick to Football: “Which players (are we) talking about coming back that can help Spurs? I agree with (Micky van de Ven, Guglielmo Vicario) – that's two.
“(Destiny) Udogie is not bad. We saw James Maddison at Tamworth, he was taken off! Tamworth are non-league. People say, "Maddison's the man", but when is he going to step up to the plate?
“He got relegated with Leicester (City) and (looks like) with Spurs. Maddison isn't bad but if you think he's going to come back and get Spurs top six, you're in cuckoo land.
“He's a talented player, but if you're a player in the Spurs dressing room and he's back in the squad, you wouldn't be looking and going, "James is back today – we're going to be fine!”.”