3:12pm: Head coach Sean McDermott announced this afternoon Oliver has indeed suffered a biceps tear. Surgery is upcoming as a result with an indefinite absence in store. A return in time for the playoffs could take place, per Ian Rapoport of NFL Network. For the time being, though, Buffalo’s defense will be without a major contributor.
10:19am: Ed Oliver exited Sunday’s game with a biceps injury. Buffalo’s top interior defender may now be in line to miss significant time. 
The Bills fear Oliver suffered a biceps tear, ESPN’s Adam Schefter reports. An MRI is pending, and the results will provide further clarity on the matter. For the time being, though, the threat of an indefinite absence looms in this case.
Being without Oliver for any extended period would deal a major blow to Buffalo’s defense. The interior of the D-line was shorthanded to begin the campaign with Larry Ogunjobi and Michael Hoecht serving six-game suspensions. Both veterans are now on the active roster, though, and they each made their season debut yesterday. Ogubnjobi and Hoecht could be in line for notable roles right away if Oliver is indeed sidelined. Jordan Phillips was elevated from the practice squad for Week 8, and he is a candidate to be signed to the active roster if needed.
Meanwhile, second-rounder T.J. Sanders is currently on injured reserve while recovering from knee surgery. Fellow rookie Deone Walker has been a mainstay up front while looking to fill in for Sanders, logging a 52% snap share on defense. That figure could increase further if Oliver winds up missing considerable time. In any case, Buffalo’s setup along the defensive interior will be something to monitor moving forward.
Oliver suffered an ankle injury during a standout Week 1 performance, although he managed to return in time for the Bills’ loss to the Falcons. A run of heavy usage was in store coming off the team’s bye, but the 27-year-old could now be forced to turn his attention to a lengthy recovery process. Needless to say, further updates on this situation will be worth watching for once the MRI is complete.
The Bills improved to 5-2 with a blowout win yesterday. The team’s defense ranks in the top 10 in points allowed per game but sits 31st against the run. Absences along the D-line have contributed to that poor showing, and the unit’s ability to improve will be greatly hindered if Oliver is forced to miss a notable stretch of the season.