Brennan secured a one-year pact with Swiss club HC Thurgau on Monday.
Brennan was waived by the Flyers on Friday, Renaud Lavoie of TVA Sports reports.
Brennan registered three assists in a 5-1 preseason victory over the Islanders on Tuesday.
The Flyers loaned Brennan to AHL Lehigh Valley on Friday.
Brennan was recalled from AHL Lehigh Valley on Wednesday.
Brennan was waived by the Flyers on Friday, Renaud Lavoie of TVA Sportsreports.
Brennan, along with four other players, were waived by the Flyers on Friday, Renaud Lavoie of TVA Sports reports.
Brennan agreed to terms on a two-year, two-way contract with the Flyers on Tuesday, Sam Carchidi of The Philadelphia Inquirer reports.
Brennan scored his first goal since the 2012-13 season in Monday's 4-3 loss to the Panthers.
Brennan was recalled from AHL Toronto on Thursday.