Ostman was put on waivers Monday for the purpose of being sent to AHL Coachella Valley.
Ostman made one NHL appearance with Seattle in the 2025-26 campaign, stopping 33 of 35 shots in a 2-0 loss to Colorado on April 16. He spent most of the 2025-26 regular season in the minors, posting a 17-15-3 record with a 2.81 GAA and a .906 save percentage in 36 outings for the Firebirds.