The 49ers placed Gross-Matos (knee) on injured reserve Saturday, Matt Maiocco of NBC Sports Bay Area reports.
Gross-Matos was unable to practice all week after injuring his knee in Week 4 against New England. The injury appears severe enough to warrant a multi-week absence for the 2020 second-round pick. Gross-Matos will be forced to sit out for at least four regular-season games, and the earliest he can return is Week 10 against Tampa Bay. Robert Beal will serve as the 49ers' main rotational edge rusher behind starters Nick Bosa and Leonard Floyd.