Murray-Macgregor, 20, joins Scarlets from the Canterbury and Crusaders pathway.
Former England Under-20s Grand Slam-winner Groves, 25, featured for Scarlets earlier this season as loan cover during two United Rugby Championship games in South Africa – starting against Lions and coming off the bench against Sharks.
Lock, Groves has also played for Bristol Bears, Sale Sharks and Western Province, and at 6ft 9in will add power and bulk to the Scarlets’ pack, as well as being a key presence at line-outs.
“I’m really excited to be joining the Scarlets permanently,” Groves said.
“Having had the opportunity to spend time with the club on loan earlier this season, I got a real feel for the environment, the people and the ambitions here, which made it an easy decision.
“This move is a fresh challenge for me at an important stage of my career and I’m looking forward to pushing myself, developing my game further and testing myself in a new environment.
“I can’t wait to join everyone in Llanelli, meet up with the boys again and get stuck into pre-season.”
Murray-Macgregor played for New Zealand Schools in 2023 and was involved in the Crusaders pre-season squad earlier this year.
He is Welsh-qualified through his mother, who is from Llanelli, and is the cousin of Wales and Scarlets centre Joe Roberts.
“I used to throw the ball around with Joe but never thought we may be at the same club together,” said Murray-Macgregor.
“The west Wales connection makes this move really special for me and my family.
“I know I have a lot of hard work ahead, but I’m looking forward to getting started, and joining up with the squad.”
Murray-Macgregor follows a similar path to Scarlets and Wales full-back Blair Murray who arrived from New Zealand in 2024.
Speaking after the announcement of Murray-Macgregor Interim Director of Rugby Nigel Davies said:
“Isaac is a player we are genuinely excited about.
“This is not just a signing based on potential; it is a signing based on the quality of environment he has come through, the level of rugby exposure he has already had and the characteristics we believe he can bring to Scarlets now and in the future.
“He has grown up in a Canterbury and Crusaders system that is known throughout the game for developing smart, skilful and highly-competitive players. That background matters because players from those environments are used to high standards, detail and accountability from a young age.”
Davies believes Murray-Macgregor fits the profile of player Scarlets want to bring into the environment and advance. The signing forms part of Scarlets’ wider strategy of identifying talented young players with the ability, character and ambition to grow within the club’s rugby programme.
“Isaac is athletic, brave, competitive and comfortable playing with the ball in space. He has good backfield instincts, strong aerial qualities and a willingness to involve himself in the game.
“He gives us another exciting option in the backfield and brings a different rugby experience into the group.
“What also stood out was his attitude. He wants to improve, he wants to challenge himself and he sees Scarlets as the right environment to take the next step in his career.
“He has come through a high-quality development pathway and now has the opportunity to connect that with his Llanelli roots here at Scarlets, which gives the signing added meaning.
“We want to build a squad with a strong core of Welsh talent, as well as being smart and creative in identifying players who can add value to what we are building.”
[Lead image: Scarlets Rugby]
