McKenna announced his retirement from the NHL on Tuesday.
McKenna was waived by the Flyers on Wednesday.
McKenna was recalled from his conditioning assignment with AHL Lehigh Valley on Tuesday.
McKenna turned aside 20 of 24 shots during Tuesday's 5-3 road loss to the Capitals.
McKenna will start in the road goal Tuesday versus the Capitals, Sam Carchidi of The Philadelphia Inquirer reports.
McKenna was snatched off the waiver wire by the Flyers from the Canucks on Friday, Elliotte Friedman of Sportsnet reports.
McKenna was waived by the Canucks on Thursday, Elliotte Friedman of Sportsnet reports.
The Senators traded McKenna, Tom Pyatt and a 2019 sixth-round pick to the Canucks in exchange for Anders Nilsson and Darren Archibald on Wednesday.
McKenna will get the starting nod on the road against the Islanders on Friday.
McKenna will defend the home net Saturday against the Capitals,