THURSDAY NIGHT FOOTBALL PREVIEW

49ers (9-4) at Seahawks (7-6)

Thursday, 5:15 p.m. (Amazon Prime)

■ Line: 49ers -3, total 43

■ 49ers player to watch: QB Brock Purdy completed 16 of 21 pass attempts with two TDS, no interceptions and

134.0 rating in his first career start last week. Purdy also ran for a TD, becoming the first rookie in the Super Bowl era with at least two TD passes, one TD run and a passer rating of at least 125 in his first career start.

■ Seahawks player to watch:

There haven’t been many bad games this season from QB Geno Smith, but last week was one of them.

Seattle desperately needs Smith to rebound from his first game with two interceptions this season and have a greater impact than he did when the teams faced off in September.

■ Key matchup: Can Seattle find the end zone against the best scoring defense in the league? The 49ers are giving up nothing defensively, and the expectation is even with a backup

QB, San Francisco is going to score on Seattle’s porous defense. The Seahawks have to be able to run the ball and hit a few big plays in the pass game to DK Metcalf and Tyler Lockett if they want to hang around.

■ Injuries: Purdy (ribs, oblique) is expected to play despite being listed as questionable. … WR Deebo Samuel (knee, ankle) is out for about three weeks. … San Francisco also will be without DT Hassan Ridgeway (pectoral), DT Kevin Givens (knee), CB Samuel Womack (concussion) and S Tarvarius Moore (knee). … Seahawks RB Kenneth Walker III (ankle) is expected to play after missing last week’s loss, while RB Deejay Dallas (ankle) is likely to miss his second straight game. … DT Al Woods (Achilles), S Ryan Neal (knee) and CB Tre Brown (illness) are all questionable.