The Melbourne Cup field changes again, with international challenger Defiantly ruled out of the race after failing a vet inspection on Derby Day. Another highly-fancied runner has been ruled out of the 2026 Melbourne Cup on vets’ orders leaving punters fuming. The Melbourne Cup 2026 field has suffered another dramatic late shake-up, with leading international contender Defiantly officially ruled out of Tuesday's $10.2 million Group 1 Lexus Melbourne.