Okposo (undisclosed) is expected to make his season debut Sunday against the Capitals.
Cozens scored his first career NHL goal in Friday's 4-3 shootout loss to the Capitals.
Ullmark stopped 29 shots in regulation and overtime and three of four shootout attempts in Friday's 4-3 loss to the Capitals.
Sheahan (face) will be in the lineup for Friday's tilt with Washington.
Okposo (undisclosed) won't play Friday against Washington, John Vogl of The Athletic reports.
Ullmark will guard the cage during Friday's road clash with the Capitals, Tom Gulitti of NHL.com reports.
The Sabres promoted Johansson from their taxi squad to their active roster Thursday, per TSN.
Dahlin has no points through four games this season.
Hutton (upper body) won't join Buffalo for its two-game road trip versus the Capitals, John Vogl of The Athletic reports.
Okposo (undisclosed) will join the Sabres' on their two-game road trip to Washington, John Vogl of The Athletic reports.
The Sabres removed Asplund from their taxi squad and loaned him to AHL Rochester on Thursday.
The Sabres added Tokarski to their taxi squad Thursday.
Ullmark (personal) was back at practice Thursday following the death of his father.
Per Cap Friendly, the Sabres reassigned Asplund to the taxi squad Wednesday.
Johansson was assigned to the taxi squad Wednesday, per CapFriendly.
Johansson came off the bench to make eight saves in Tuesday's 3-0 loss to the Flyers.
Sheahan went to the locker room in the third period of Tuesday's game versus the Flyers after taking a puck to the face, Lance Lysowski of The Buffalo News reports.
Okposo (undisclosed) was placed on injured reserve Tuesday, per CapFriendly.
Hutton did not return for the third period of Tuesday's game in Philadelphia following a collision in the second period.
Thompson is not dressed for Tuesday's game against the Flyers and is a healthy scratch.
Ullmark (personal) will not suit up for Tuesday's game against the Flyers, Lance Lysowski of The Buffalo News reports.
Hutton will be between the pipes Tuesday in Philadelphia, Lance Lysowski of The Buffalo News reports.,
Asplund was recalled from the taxi squad Tuesday.
Sheahan picked up an assist in Monday's victory over Philadelphia.
Cozens played on Buffalo's second line during Monday's win over the Flyers.