Ustimenko was reassigned to AHL Lehigh Valley on Wednesday.
Ustimenko will be called up from AHL Lehigh Valley and will serve as the No. 2 option versus Carolina on Monday, Adam Kimelman of NHL.com reports.
Ustimenko was called up to the taxi squad Wednesday, per CapFriendly.
The Flyers loaned Ustimenko to AHL Lehigh Valley on Wednesday, Jordan Hall of NBC Sports Philadelphia reports.
Ustimenko was added to Philadelphia's taxi squad Tuesday.
Ustimenko (hip) was on the ice with the Flyers' third group at practice Thursday, Olivia Reiner of the Philadelphia Inquirer reports.
Ustimenko will be sidelined 4-5 months after having surgery to repair a torn labrum.
Ustimenko has been loaned to HC Gomel of the Belarusian Extraliga.
Ustimenko signed an entry-level contract with the Flyers on Wednesday.