Not having Greer would be another blow to an already ragged secondary in a critical game for the Bills' playoff hopes.
Strong safety Donte Whitner also is expected to miss Sunday's game at Arrowhead Stadium, although the source noted there's a chance Whitner might try to play. Whitner separated his shoulder Nov. 2 against the New York Jets. He missed one game but made a surprising return Monday night to play his hometown Cleveland Browns.
Neither Whitner nor Greer finished the game.
Greer suffered a knee injury. He missed practice again Thursday, but BuffaloBills.com reported he worked out in the weight room.
Greer has started all 10 games for the Bills. He has two interceptions, both returned for touchdowns. Greer has 33 tackles and nine passes defensed, according to the Bills' internal stats.
So the Bills won't go into Sunday's game with only three cornerbacks, they're expected to sign Dustin Fox off their practice squad.
BuffaloBills.com reported receiver Josh Reed "stands a good chance" of playing against the Chiefs. Reed has missed the past three games with a sprained ankle, but has practiced two straight days.