The decision was made after he ceded No. 72, the number he has worn throughout much of his junior career, to veteran goaltender Sergei Bobrovsky.
McKenna told reporters Thursday he would give up the number that both have worn throughout their careers out of deference to the two-time Stanley Cup champ, who signed a three-year, $21-million deal with the Maple Leafs on Wednesday.
The 18-year-old wore No. 72 at Penn State this season and with the WHL’s Medicine Hat Tigers, and his backup Nos. 9 and 27 are retired by the franchise in honour of Charlie Conacher, Ted Kennedy, Darryl Sittler and Frank Mahovlich.
McKenna will be the fourth Leafs player to wear No. 92 following Jeff O’Neil, Igor Ozhiganov and, most recently, Alexander Nylander.
The Maple Leafs and McKenna agreed to his three-year, entry-level contract on Friday.