Running back Isiah Pacheco (shoulder contusion), safety Bryan Cook (sprained ankle), left tackle Donovan Smith (neck stinger) and linebacker Drue Tranquill (concussion protocol) all missed practice on Wednesday and Thursday.
The team-leading rusher has 988 total yards (779 yards rushing) and seven total touchdowns.
If Pacheco is out, the Chiefs are left with McKinnon, who is likely to play, and Clyde Edwards-Helaire. They will likely call up rookie Deneric Prince or veteran La’Mical Perine from the practice squad on game day to fill in a third RB role.
If Smith can’t play on Sunday, rookie offensive tackle Wanya Morris has stepped in for Smith in the past two games and has performed well under the circumstances.
Veteran safety Mike Edwards will likely start in place of Cook. Edwards has rotated in and seen a plethora of snaps this season, and he has tallied 28 tackles and an interception.
Second-year LB Jack Cochrane stepped in for Tranquill against the Packers but with Bolton on the mend and expected to play, the Chiefs may not need Cochrane as much.
The Bills are 6-6 and are fighting for their playoff hopes as they come to Arrowhead Stadium off of their bye week on Sunday at 3:25 p.m.