Gardiner played in 80 games for the Maple Leafs, scoring 10 goals and recording 21 assists. His 21:04 time on ice average was the second-highest on the team.
The former Anaheim Ducks first-round pick has spent the last three seasons with the Maple Leafs and the Toronto Marlies of the AHL.
On Monday, the Maple Leafs signed forwardDaniel Winnik to a $1.3 million deal.
Toronto went 38-36 and failed to make the playoffs last season. The team has not won a playoff series since 2003-04. In April, the Maple Leafs hired Brendan Shanahan to serve as the team's president and alternate governor. In July, the team fired two top front office executives in a "restructuring" move.
- Alex Hampl