Tomas was born in Wellington and grew up in Dubbo, both in regional NSW. He moved to Sydney and studied a Bachelor of Medical Science at the University of Sydney, also playing rugby for Sydney University. In 2016 he commenced his first year in the Doctor of Medicine degree at Sydney University and started playing rugby professionally for the NSW Waratahs, leading to his selection for the Australian National Rugby Union Team, the Wallabies. In order to represent his country on at an international level, Tomas suspended his studies in the Doctor of Medicine but completed a Master of Public Health and a Master of Philosophy (Medicine), both at the University of Sydney. In 2020 he moved to Perth to play for the Western Force Rugby team, playing over eighty super Super rugby Rugby games and being capped for his country on twenty-seven occasions. He is hoping to participate in the 2023 Rugby World Cup in France. Tomas will commence a Master of International Health and Tropical Medicine as a John Monash Scholar at Oxford University. In the long term, he wants to try and help close the gap in health outcomes between the regional and metropolitan areas of Australia.