There was a surprise on the 49ers’ list of inactives for the season opener in Detroit. Rookie running back Trey Sermon will not suit up for San Francisco after getting a full week of practice in and not showing up on the team’s Friday injury report. Sermon missed part of the preseason with an ankle issue but there was no indication during the week it was still a problem, and there’s no word on why he’s not suiting up against the Lions.

The running backs Sunday will be Raheem Mostert, Elijah Mitchell and JaMycal Hasty.

San Francisco will also go into Week 1 without a pair of defensive starters. Defensive lineman Javon Kinlaw and cornerback Emmanuel Moseley are both on the 49ers’ inactive list for the opener after getting labeled as ‘doubtful’ in Friday’s injury report.

Kinlaw is dealing with a knee injury that hampered him during training camp. Moseley is also working through a knee issue. Both players were on the field getting workouts in before the game.

Here’s the full list of players not suiting up for San Francisco:

CB Emmanuel Moseley
DL Javon Kinlaw
CB Josh Norman
RB Trey Sermon
OL Aaron Banks

Norman only joined the team Monday and is still working into playing shape, and Banks, a rookie second-round pick missed most of the preseason with a shoulder issue.