UFC 273 Loses Marcin Tybura-Jairzinho Rozenstruik Matchup Due to Tybura Illness
These days, Ultimate Fighting Championship fights are not official until the cage door locks behind the competitors.
https://www.sherdog.com/news/news/UFC-273-Loses-Marcin-TyburaJairzinho-Rozenstruik-Matchup-Due-to-Tybura-Illness-185860