Career
Before playing in the NHL, Blais played three seasons with the Victoriaville Tigres and one season with the Charlottetown Islanders of the Quebec Major Junior Hockey League (QMJHL).
He was drafted 176th overall by the St. Louis Blues of the 2014 NHL entry draft. On November 14, 2015, Blais signed a three-year entry-level contract to join the Blues. He was sent down to play for their AHL-affiliate Chicago Wolves and San Antonio Rampage.
On October 14, 2017, the Blues called him up and Blais made his NHL debut in a 2–1 loss against the Tampa Bay Lightning. On October 19, he recorded his first NHL point after assisting on a Robert Bortuzzo goal in a 4–3 win against the Colorado Avalanche. On November 25, Blais scored his first NHL goal on the powerplay against Devan Dubnyk in a 6–3 win against the Minnesota Wild. He helped the Blues during the playoffs. They defeated the Winnipeg Jets, Dallas Stars, and San Jose Sharks. They went on to defeat the Boston Bruins four games to three in the Final to win the first Stanley Cup in Blues franchise history. On July 1, 2019, Blais signed a one-year contract to stay with the Blues.
On July 23, 2021, the Blues traded Blais along with a 2022 second-round draft pick to the New York Rangers in exchange for Pavel Buchnevich. On July 1, 2019, Blais signed a one-year contract to stay with the Rangers.
On February 9, 2023, the Rangers traded Blais along with Hunter Skinner, a 2023 conditional first-round draft pick, a 2024 conditional fourth-round draft pick back to the St. Louis Blues in exchange for Niko Mikkola and Vladimir Tarasenko. On July 1, 2019, Blais signed a one-year contract to stay with the Blues.
On August 22, 2024, Blais signed a one-year contract to join the Abbotsford Canucks of the American Hockey League (AHL). He helped the Canucks during the playoffs. They defeated the Coachella Valley Firebirds, Colorado Eagles, and Texas Stars. They went on to defeat the Charlotte Checkers four games to two in the Final to win the first Calder Cup in Canucks franchise history.
On July 1, 2025, Blais signed a one-year contract to join the Montreal Canadiens. Before he was able to play for the Habs, he was placed onto waivers and his contract was picked up by the Toronto Maple Leafs the next day. He scored one goal and recorded two assists in 8 regular season games with the Leafs.
On November 26, 2025, the Leafs placed Blais back onto waivers and his contract was picked back up by the Montreal Canadiens. He scored two goals and recorded three assists in 13 regular season games with the Canadiens.
On July 1, 2026, Blais signed a two-year contract to join the Ottawa Senators.
Canada