Okposo is recovering from a bruised knee after he was hit by a shot in practice on Monday. Kulikov has, in layman's terms, a "bruised butt" from a hit in the third period of his own preseason debut last Thursday and will begin to skate on Friday, while Bogosian began skating alone on Thursday to rehab a groin injury.
The list continues: Daniel Catenacci also left Wednesday's game early with an injury to his hamstring and Nick Baptiste saw a promising camp cut short with a lower-back injury. Tyson Strachan will return to the ice from an ankle injury on Friday.
With a week remaining prior to the Sabres' regular season opener against Montreal, it's possible that some or all of O'Reilly, Okposo, Bogosian and Kulikov can recover in time to crack the opening night lineup. But their absence now will change the way Bylsma has to look at his team's final preseason game.
What would normally be a dress rehearsal for the opening night roster now becomes another chance for certain guys to continue to prove their worth. Particularly on defense, the injury situation compounded with the fact that restricted free agent Rasmus Ristolainen remains unsigned has opened the door for guys for more competition.
Ristolainen has been practicing with the team and skated with Josh Gorges, his partner for most of last season, on Thursday.
"I'm acting right now in practice and playing [him] on a pair like he's going to be there," Bylsma said. "That might change next week when we get to practice if he still remains unsigned."
Between Ristolainen's situation, the current injuries and late starts to camp for O'Reilly, Kulikov and Jack Eichel due to their involvement with the World Cup, the Sabres have yet to even get their regular power-play units on the ice.
"It's been kind of a different process," Bylsma said. "I don't particularly like the fact that we haven't had a power play together on the ice yet, at least the one that we see us having at the start of the season, and I could say that the same about line combinations and some lines."
Luckily, the Sabres seem to have some good options to fill in should they need them. With defensemen Erik Burgdoerfer and Brady Austin among the six players reassigned to Rochester on Thursday (along with goalie Linus Ullmark and forwards Justin Bailey, Cole Schneider and Jean Dupuy), the remaining players with a chance to crack the lineup on defense are Casey Nelson, Justin Falk and Brendan Guhle.
Nelson has already earned plenty of praise for his "commanding" presence at camp from Bylsma. Falk has gotten several looks in the preseason and has 171 games of NHL experience already under his belt. Guhle has played some of his best hockey as of late and can play up to nine NHL games before a decision will need to be made whether or not to send him back for another year of junior hockey.
Among the forwards still looking to crack the lineup are Derek Grant, who might already be a lock with five points (2+3) in five preseason games, Alex Nylander, Hudson Fasching and Cal O'Reilly.
Buffalo's game in Ottawa on Friday begins at 7:30 p.m. and can be heard live on WGR 550 with Dan Dunleavy and Rob Ray on the call.