Reimer suffered a lower-body ailment early in the first period, then Mrazek was steamrolled by Leafs forward Kyle Clifford while chasing down a loose puck in the second frame.
Clifford was assessed a charging penalty on the play. Mrazek was helped off the ice and gave way to Ayres, who works as the Toronto Marlies' Zamboni driver, according to NHL.com's Mike Zeisberger.
Ayres will make $500 for his appearance and get to keep his game-worn jersey, according to TSN's Frank Seravalli.
Carolina scored on the ensuing power play to make it 4-1, but the Leafs put two past Ayres to cut the deficit to 4-3.