Robbie has been outstanding in his first two seasons with the Leopards, reviving his international career and being a cornerstone of the club’s successful campaigns which included the 2023 Challenge Cup triumph. He was voted Coaches’ Player of the Year in the club’s 2024 awards.

Signed from Warrington Wolves, he is a product of the Leeds Rhinos academy and since making his senior debut for Leeds in Round Six of the 2014 Super League season against London he is closing in on 250 career games.

In 2015 Mulhern was sent on loan to Hunslet Hawks, where he was a regular starter for the Championship side. These high-quality performances at such a young age caught the eye of then Hull KR Head Coach, and current Head of Rugby at Leigh, Chris Chester who signed him up ahead of the 2016 Super League season.

Robbie spent five years in the East Riding of Yorkshire and earned promotion back to Super League for KR in 2017. He scored 11 tries in 110 games for the Robins before he signed for Warrington Wolves in a two-year swap deal for Luis Johnson. He has won representative honours for Ireland, England Knights and England.