The full Nottingham Forest allocation of 3,320 tickets has been sold while Leicester are advising their supporters to move quickly if they wish to attend.
The Foxes biggest home attendance of the season to date was 23,357 against Bournemouth but the combination of an excellent run of form and a local derby will see that figure beaten by quite a long way this weekend.
One man the two clubs have in common is in the news this week as Martin O'Neill has confirmed he will be the new Republic of Ireland manager, assisted by Roy Keane.
"I think I'm the bad cop and he's the bad, bad cop," O'Neill told ITV on Tuesday.