There is a waiting list of players wanting to play in the cup. Players who do a no-show are put out of the cup and the first player in the waiting list is matched with the other player.
However, I'm not entirely sure that's fair if you get eliminated to get back into the waiting list. After all it means you can get a lot of shots at winning the prizes and the podium.
If you want players to have a second chance at coming back, then you have to create a double elimination tournament. That's a little complex to make function here strictly online without instant messaging.

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