Bernard (pectoral) was a limited participant during practice Thursday, Alaina Getzenberg of ESPN.com reports.
Bernard was already ruled out for Week 4 against the Ravens on Tuesday, but his return to the field is a positive sign of his potential availability for Week 5. However, in a separate tweet, Getzenberg, mentioned he was on the field in a red non-contact jersey, so it's hard to gauge how well he is doing. Either way, Baylon Spector should be the Bills' starting middle linebacker against Baltimore on Sunday.