Blue (ankle) is in a walking boot and won't play in Thursday's preseason game against Miami, Phillip Heilman of The Athletic reports.
Blue's absence could provide a nice opportunity for fifth-round pick Ryquell Armstead, who passed through the final stage of the NFL's concussion protocol Sunday. The rookie still has time to make his case for a backup role, though Blue appeared to have the lead for the No. 2 job before he injured his ankle. The messy depth situation could encourage Jacksonville to give Leonard Fournette all the work he can handle.