Okposo was hurt when he and Senators forward Bobby Ryan didn't see each other and collided early in the second period of Buffalo's 4-3 shootout victory at Ottawa on Thursday.
Coach Phil Housley on Friday said he was encouraged by how Okposo looked on the team's flight home.
"Just seeing him last night, I thought he was in a good place," Housley said. "Obviously there's things that can happen down the road. But from my perspective, he was in good spirits, so that was a good sign."
A head injury was an issue for Okposo last year when concussion-related symptoms nearly derailed his career. Okposo lost weight and had difficulty sleeping and spent a week in the hospital after sustaining a concussion during what he called a routine hit in practice.
The 11-year veteran is tied for third on the Sabres with 38 points (11 goals and 27 assists) in 65 games this season.
Center Ryan O'Reilly described seeing Okposo lying on the ice as "awful," understanding what his teammate went through last year.
"You're just praying that he's OK," O'Reilly said. "It's tough. He's been through a lot, and hopefully it's a speedy recovery and he's back soon."
The injury is the latest to affect the Eastern Conference's last-place team. Leading scorer Jack Eichel has missed nearly a month with a sprained right ankle.
The Sabres, who host Vegas on Saturday, filled Okposo's roster spot by recalling forward Justin Bailey from their AHL affiliate in Rochester, New York.