BUFFALO, N.Y. -- The Buffalo Bills' offense will likely be without a key player for Sunday's game against the Indianapolis Colts, as starting rookie right tackle Spencer Brown was placed on the reserve/COVID-19 list Thursday and is expected to miss the game.

Brown missed two games coming off the team's bye because of a back injury but returned against the New York Jets last week and helped the offense put up a season-best performance, totaling season highs in points (45) and yards (489).

Without Brown -- who has started four games this season -- the right side of the line will have to adjust yet again. Right guard Daryl Williams could move to the third-round pick's spot at right tackle if needed. Cody Ford, a 2019 second-round pick, started at right guard in the 9-6 loss to the Jacksonville Jaguars and underperformed. Ryan Bates is another candidate at guard.

Starting guard Jon Feliciano is not eligible to come off injured reserve until after the game against the Colts.

A short week awaits the Bills with a matchup in New Orleans on Thanksgiving night, which means Brown is also likely to miss that game.

The Bills (6-3) are in a tight AFC East race with the New England Patriots (6-4) -- the teams' two matchups are scheduled for December.

Wide receiver Jake Kumerow was removed from the reserve/COVID-19 list Thursday, while defensive tackle Star Lotulelei remains on the list. Backup quarterback Mitchell Trubisky was removed from the list Monday. 

Since Nov. 2, the Bills have placed six players on the reserve/COVID-19 list. There has been at least one Bills player on the list every day during that stretch.