Gilmore along with backup running back Anthony Dixon (hamstring) are listed as questionable on the Bills' injury report released Friday. Gilmore is a two-year starter and his injury is of significant concern because of the Bears' potent receiving group led by Brandon Marshall and Alshon Jeffery.
Buffalo's defense will already be without starting outside linebacker Kiko Alonso, who is expected to miss the season with a left knee injury. Alonso's backup, Nigel Bradham, is unavailable because he is serving a one-game suspension for violating the NFL's substance abuse policy.
That leaves Buffalo turning to rookie third-round draft pick Preston Brown to fill the spot.
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