In a statement released by the Steelers on Tuesday night, the 31-year-old Canadian has been forced to hang up his skates after four successful seasons in South Yorkshire due to a combination on long-lasting injuries which have finally taken their toll.
"I can’t begin to tell you what a difficult decision this has been to make. Hockey has been my life and I passionately love the game," said Roy. “From the moment I arrived in Sheffield I knew I had found a new home and a place i wanted to play in until my retirement. I just didn’t expect the retirement to come so soon
“The reality is that my body isn’t responding to the injuries I have. I get up in the morning and struggle to walk; I can’t hold a pen properly because my wrists are so bad.
“I wanted to come home and rest up and then be in the best shape of my life for the new season. It was soon pretty clear to me that this wouldn’t be possible. I kept giving it “another week” but the time came when I had to make a decision.
"It’s the toughest call I’ve ever had to make and I put off calling Thommo for as long as possible in case things changed. Unfortunately they didn’t."
Roy first arrived in the UK in 2014, having previously won the ECHL Kelly Cup with Florida Everblades in 2012. In his first season under then Steelers' head coach Gerad Adams, he won the the first of two Elite League regular season titles, repeating the success the following year under Paul Thompson.
A play-off title followed under head coach Thompson in 2017 before his first barren season with the Steelers came in 2017-18. In his four seasons with the club - which included two Champions Hockey League campaigns - Roy played 273 games in which he scored 147 goals and 297 points.
Having signed a two-year deal at the start of the 2017-18 campaign, Roy was the only Steelers' import expected to return for the 2018-19 campaign as Thompson sets about a major overhaul of his squad in an attempt to close the gap on two-time EIHL champions Cardiff Devils.
His decision to retire will be a bitter blow for Thompson, who will have taken aback by the news having only spoken earlier in the week about what a bog role the talisman had to play next season. The former GB coach was quick to outline the impact the winger had had during his time in Sheffield.
"Mathieu will go down as one of the greats at this club,” said Thompson. “He was a difference maker. He struggled with injuries so much and just tried to play through them, such was his character and determination.
"I know it killed him, especially at the start of last season, when he wasn’t producing as he wanted to. It was to his credit that he found a way to return and score us some huge goals for us like the one in the play-off semi-final against Nottingham. He again led the team in scoring which is incredible when you know what he went through.
"His team-mates will miss him as a popular member of the room and I will miss him as a key player for me in our time together. The one thing we will all have, though, are the very many fantastic memories he gave us - the goals, the blocked shots and, most of all, three championships in four seasons."