Hildeby was assigned to AHL Toronto on Thursday.
Hildeby has seen sporadic playing time for the Maple Leafs this year, and he had started in just three of the team's last nine games. He went 1-2-0 with a 2.97 GAA and .868 save percentage during that time but should see more consistent opportunities in the minors. Matt Murray was recalled by the Maple Leafs and should serve as Joseph Woll's backup while Anthony Stolarz (knee) remains sidelined.