Down through the years, Irish rugby has made the most of World Rugby's eligibility rules to convert some top-class players to represent Ireland at test level. Here are 9 of the best players who were eligible to play for Ireland but chose not to. Isa Nacewa (Fiji)One of the great "what could have been" players in Irish rugby history. AdvertisementLawrence Dallaglio (England)A pantomime villain to many Irish rugby fans, Lawrence Dallaglio actually came incredibly close to lining out in green. Austin Healey (England)Like Dallaglio, Austin Healey is a figure widely disliked by Irish rugby fans, but things could have been oh so different.