Career
Despite being born and raised in Queensland, Jeffries initially made a name for himself playing for Sydney University in the Shute Shield. He suffered injury problems during the early part of his career in Melbourne, however he regained full fitness towards the end of the season and made his debut off the replacements bench in the Rebels final match of the campaign, a 40-7 defeat by the Bulls in Pretoria. Following the departures of experienced second-row forwards Hugh Pyle and Chris Thomson at the conclusion of the 2014 season, the Rebels announced that Jeffries would be a part of their first-team squad for at least the next 2 years.
Jeffries represented Australia Under 20 at the 2012 Institutional Review Board Junior World Championship in South Africa.