An Ivory Coast international on the books of a London rival is among those to have been linked with a big-money move to Spurs.
O’Hara concedes that the 26-year-old is a fine player, and one proven in the Premier League, but feels Mauricio Pochettino already has enough options in wide attacking areas.
The former Spurs midfielder told Love Sport Radio of the links to a prized asset at Palace: “Zaha is a fantastic player and a great prospect but I think Tottenham need to be looking at someone now who is going to change that team and add to that team.
“Does Zaha start in front of [Lucas] Moura or [Christian] Eriksen or Son? I don't think so.
“I think they need to really strengthen in midfield. I'd like to see them sign a world-class midfielder. That's the first thing Tottenham need to do.
“They need a couple but I'd like to see them go for someone special just to say 'we've arrived now, we've got our stadium, this is what we're thinking and this is where we're going'. They don't need to sign bit-part players.”
The focus then was on pumping funds into the newly-constructed Tottenham Hotspur Stadium.
With that venue now open and Pochettino’s side chasing down a top-four finish and Champions League glory, O’Hara is looking for a show of ambition to be made on the field.
He added when asked what Spurs need to be investing: “If you want to compete and contend at the top for the title, you have to spend. That's just the way it is. World-class players cost money.
“Tottenham have done unbelievably in terms of not signing anyone and still competing - but they haven't won a trophy.
“If they really want to stay competing with the Man City's and Liverpool's, then they need to spend £100m.
“I think they need two and if you can't get two world-class players for £100m, then the game really has gone mad.”