OFB-9

If it's a draw, then there's no need to change anything! And even if it's 1-0, it's not critical, because with an odd number of participants, the winner of the first round has to play against the loser! In general, this is an imagined problem, more like a principle. Just say it directly.

There's no exaggeration here. Two players, and they're not exactly newcomers, didn't find the time (or desire) in 3 weeks to let the tournament organizers know about their situation, and that's why things turned out the way they did. By the way, why did you decide that nothing needs to be changed? There was a draw in the first round, and we have an even number of people... I don't understand.