49ers pregame: Brock Purdy returns, Josh Dobbs will back up rather than Brandon Allen

ORCHARD PARK, N.Y. — Quarterback Brandon Allen, the 49ers’ spot starter in last Sunday’s loss at Green Bay, has been demoted to the No. 3 emergency role for tonight’s game against the Buffalo Bills.

Brock Purdy is expected to start after a right (throwing) shoulder issue kept him out of that 38-10 defeat in Green Bay. Josh Dobbs, for the second straight game, will serve as the immediate backup in what would be his 49ers debut.

Purdy and the 49ers arrived wearing winter coats on their bodies and all-business expressions on their faces at snow-covered Highmark Stadium three hours before kickoff. An hour later, they were on the field for warmups, including Purdy, who was limited in Wednesday and Thursday sessions before Friday’s full action in a brief walkthrough.

Over two feet of lake-effect snow fell on this suburb some 10 miles south of downtown Buffalo since Saturday. Conditions eased as a tarp was removed from the synthetic turf and a John Deere tractor cleared further snow from the field. The weather conditions provided the biggest mystery ahead of the 8:20 p.m. ET kickoff.

NINERS INACTIVES

The 49ers (5-6) announced Friday a slew of injured players who were ruled out: defensive end Nick Bosa (oblique/hip), left tackle Trent Williams (ankle), cornerback Deommodore Lenoir (knee), guard Aaron Banks (concussion) and defensive tackle Jordan Elliott (concussion). Added to the inactive list were Allen and linebacker Demetrius Flannigan Fowles (knee).

BILLS INACTIVES

Wide receiver Keon Coleman and tight end Dalton Kincaid headline the Bills’ inactive list, which is rounded out by cornerback Kaiir Elam, linebacker Eddie Ulofoshio, defensive end Javon Solomon, offensive lineman Will Clapp and quarterback Mike White.

NFC WEST RACE

The 49ers are the last of four NFC West teams playing on the road today. The Seattle Seahawks (7-7) emerged alone in first place after rallying for a 26-21 win over the New York Jets (3-9). The Arizona Cardinals (6-6) lost 23-22 to the Minnesota Vikings (10-2). In New Orleans, the Rams (6-6) won 21-14 at the New Orleans Saints, thus leaving the 49ers alone in last place, at least until this game’s outcome is settled.