The deal is worth the league minimum of $700,000, according to TSN's Darren Dreger.
The 40-year-old inked a three-year contract with the Toronto Maple Leafs ahead of the 2017-18 campaign after 19 seasons with the Sharks. In June 2019, he was traded to the Carolina Hurricanes, who bought out the final year of his deal days later.
Marleau recorded 16 goals and 37 points in 82 games for the Maple Leafs last season.
Despite his age, the 6-foot-2 Marleau has been one of the league's most durable players, suiting up in 788 consecutive contests over 10 campaigns.
The Saskatchewan native is the Sharks' all-time leader in games played (1,493), points (1,082), and goals (508). He ranks second in assists with 574.
San Jose selected Marleau with the second overall pick in the 1997 NHL Draft.