Vilen (upper body) was activated from the injured non-roster list and assigned to AHL Utica on Tuesday.
Vilen (upper body) will be out for about 3-4 weeks, Catherine Bogart of the Devils' official site reported Tuesday.
Vilen was demoted to AHL Utica by the Devils on Friday, Mike Morreale of NHL.com reports.
Vilen was assigned from the Liiga's Pelicans to AHL Utica on Monday.
Vilen signed a three-year, entry-level contract with the Devils on Thursday.