 He made his competitive debut for Munster on 1 September 2018, coming off the bench in their opening 2018–19 Pro14 fixture against Cheetahs in Thomond Park, a game which Munster won 38–0.Coombes signed a two-year contract with Munster in October 2018, a deal that saw him join the senior team from the 2019–20 season.He scored his first tries for Munster in their 29–10 win against Welsh side Scarlets during round 13 of the 2019–20 Pro14 on 29 February 2020.