[3] Reffell made his debut for Leicester Tigers on 10 November 2017 in a 33–31 defeat against Bath at the Rec in the Anglo-Welsh Cup.
[4][5] In March 2020, Reffell won the Premiership Rugby Cup Breakthrough Player award for his performances in that year's competition.
[6] His form for Leicester in the 2020–21 season lead to speculation that he was in contention to be capped by either England or Wales, but he remained uncapped.
[12] Reffell scored the winning try as Leicester beat Exeter Chiefs on the opening day of the 2024-25 Premiership Rugby season.
[15] On 2 July 2022 Reffell made his debut for Wales in their 32–29 defeat to South Africa at Loftus Versfeld in Pretoria.