Lettieri was sent down to AHL Toronto on Saturday, per David Alter of The Hockey News.
Lettieri was optioned back to the AHL in a corresponding move to Cole McWard's call-up. The latter was likely called up due to Morgan Rielly's injury Saturday, making Lettieri the top candidate in the forward group to be sent down. During his stint with the Maple Leafs, the 31-year-old Lettieri posted a goal, eight shots on net, 24 hits and nine blocked shots over eight appearances. He'll likely see more action in the NHL at a later date this season.