Mitchell suffered an MCL knee injury in Monday night's 4-3 overtime loss to the New York Islanders while Toskala had to leave the game after tweaking a groin injury.
MacDonald, who has spent most of the season with the Toronto Marlies of the American Hockey League, has a 0-3-0 record with the Leafs this season. He posted a 3.35 goals-against average and .875 save percentage with the NHL club.
Hanson ranks first on the Marlies in scoring and second among all AHL rookies with 18 points (eight goals, 10 assists) in 18 games.
Mitchell has nine points (2-7) in 22 games this season.
Toskala has a 1-4-2 mark with a 3.91 GAA and .865 save percentage.