The 23-year-old Swede had 23 points (five goals, 18 assists) in 61 regular-season games with the Maple Leafs in 2021-22. He also appeared in two playoff games.
Liljegren was selected by Toronto in the first round, 17th overall, of the 2017 draft.
He has 24 points (five goals, 19 assists) in 74 career regular-season games with the Maple Leafs.
Liljegren has made 148 regular-season appearances with the American Hockey League's Toronto Marlies, putting up 73 points (11 goals, 62 assists). He won a Calder Cup in 2018 with the Marlies.