Hayes began his professional career with the New York Rangers after choosing not to sign with Chicago initially. He later moved to the Winnipeg Jets via a trade in 2019 before signing with the Flyers as a free agent. His six-year stint in Philadelphia included a strong first season, where he posted 41 points in 69 games, and a standout playoff run in 2020, tallying 13 points in 16 games as the Flyers advanced to the second round.
In the following season, Hayes’ production declined, recording 31 points in 55 games. He underwent surgery for a sports hernia, and the 2021-22 campaign brought further health challenges, including a blood infection and the personal tragedy of his brother Jimmy’s death, who had also played in the NHL. Despite these obstacles, Hayes delivered 31 points in 48 games and was a finalist for the Bill Masterton Memorial Trophy for his perseverance and dedication to the sport. He finished his Flyers tenure with 54 points in his final season with the team, after briefly filling a top-line role due to an injury to Sean Couturier.
In the summer of 2023, Hayes was traded to the St. Louis Blues, where he played one season, recording 13 goals and 16 assists in 76 games. The following year, he was traded to the Pittsburgh Penguins in a deal that sent future considerations the other way, contributing 13 goals and 10 assists in 64 games. His 2025-26 season included 28 appearances with eight points, often being a healthy scratch.
Overall, Hayes retired with 185 goals and 261 assists in 805 regular-season games, plus eight goals and 18 assists in 56 playoff appearances. His career also included a total of 600-plus NHL games played, highlighted by memorable playoff performances and leadership on several teams during his tenure. The move to the KHL marks a new chapter for Hayes as he continues his professional hockey career overseas.