Carlo, who has one season remaining on a six-year, $24.6 million contract ($4.1 million average annual value) he signed with the Boston Bruins on July 14, 2021, can become an unrestricted free agent after next season.
Carlo had seven assists in 55 games for the Maple Leafs this season. He was acquired by Toronto in a trade with Boston on March 7, 2025, for forward Fraser Minten and two draft picks.
Selected by Boston in the second round (No. 37) of the 2015 NHL Draft, Carlo has 119 points (29 goals, 90 assists) in 692 regular-season games for the Bruins and Maple Leafs and 14 points (five goals, nine assists) in 85 Stanley Cup Playoff games.
The move is the latest by Toronto, which acquired goalie Samuel Ersson (later traded to the Ottawa Senators) and defenseman Emil Andrae in a trade with the Philadelphia Flyers on June 16 for goalie Joseph Woll and Simon Benoit. The next day, the Maple Leafs hired Jim Hiller as coach, replacing Craig Berube.
Two days later, the Maple Leafs acquired defenseman Darren Raddysh in a trade with the Tampa Bay Lightning for Toronto's fifth-round selection in the 2026 draft. Raddysh then signed an eight-year contract with Toronto.
The Maple Leafs also selected forward Gavin McKenna with the No. 1 pick on Friday.
The Blues acquired forward Mason McTavish from the Anaheim Ducks on Friday for two first-round picks in the 2026 draft. They also traded forward Jordan Kyrou to the Washington Capitals on Tuesday for forwards Connor McMichael and Milton Gastrin, and a first-round pick this year, which was later traded to the Ducks.