The UFC could make a plan B for all main events, one or two fighters not on the card but designated and willing to train and be ready to step in if either of the scheduled main event fighters pulls out. The substitute fighters might have to be compensated for their extra work, but at least the scramble to find someone-anyone to step in, with mismatches sometimes resulting, would be avoided, and the whole last minute change of advertising etc. would be less. And the "they just rolled off the couch" excuse would go away.