Okposo was injured in a collision with Ottawa Senators forward Bobby Ryan during the second period of the Sabres' 4-3 shootout win Thursday.
"It was an unfortunate play, they just ran into each other," Sabres coach Phil Housley said. "So we'll just have to go day to day with that, see where he's at."
Okposo, 29, was hospitalized in March 2017 with what he later described as complications from medication used after being treated for a concussion.
"From my personal knowledge, 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, I thought he was in good spirits, so that's a good sign."
Okposo, in the second season of a seven-year contract he signed with Buffalo as an unrestricted free agent, has 38 points (11 goals, 27 assists) in 65 games this season.
"I didn't see the hit, but you see him on the ice after and just praying he's OK," Sabres center Ryan O'Reilly said. "It's a tough bounce, he's been through a lot, but hopefully it's a speedy recovery and he's back with us soon."
