Marsh has entered the league's concussion protocol, Matt Maiocco of NBC Sports Bay Area reports.
It's unclear exactly as to where Marsh obtained the injury, but there's a chance he'll be forced to miss next week's game. Given the nature of the league's stance on head injuries, Marsh will have to prove beyond all doubt that he is symptom-free before he can make a return to the gridiron.
Marsh had four tackles (three solo) and 2.5 sacks in Thursday's 34-3 win over Oakland.
Marsh was a force off the edge against a Raiders offensive line that was without tackle Donald Penn, setting a new career high in sacks. The 26-year-old had just one sack coming into Thursday's contest, and his situational role limits his upside as an IDP option despite the career day.
Marsh exited practice early Friday due to a groin injury, the San Francisco Chronicle reports.
The extent of Marsh's injury hasn't been revealed, so it's best to consider him day-to-day unless something suggests otherwise. Assuming the issue doesn't cost him regular-season action, March should rotate in on the defensive line for the 49ers in 2018 after playing a career-high 457 defensive snaps last season.
A late-season waiver pickup for the 49ers, Marsh upgraded the team's dormant pass rush over the final six games of 2017, providing two sacks and 11 tackles. He also established himself as a mainstay on the team's kick-coverage and return units, with only Dekoda Watson playing more snaps on special teams from Week 12 onward. Look for the 25-year-old to rotate in regularly on defense and play a prominent role on special teams again in 2018.
|17||12/30/18||@ LAR||4:25 pm|
|2017||New England Patriots||9||19||16.0||3||1||0||0||0.0||0||0||0|
|2017||San Francisco 49ers||6||11||10.0||1||2||0||0||0.0||0||0||0|
|2018||San Francisco 49ers||13||27||19.0||8||3.5||0||0||0.0||0||0||0|
|2017||New England Patriots||9||0||0||---||0||0||0|
|2017||San Francisco 49ers||6||0||0||---||0||0||0|
|2018||San Francisco 49ers||13||0||0||---||0||0||0|
|Year||Team||G||Fum||Lost||Fum Forced||Own Rec||Opp Rec||Yds||Tot Rec||TD|
|2017||New England Patriots||9||0||0||1||0||0||0||0||0|
|2017||San Francisco 49ers||6||0||0||2||0||0||0||0||0|
|2018||San Francisco 49ers||13||0||0||0||0||1||0||1||0|