Warner got hurt on the San Francisco's last defensive possession. It appeared that the fourth-year pro suffered a non-contact knee injury.
On a slightly positive note, the 49ers have officially ruled Warner questionable to return with an ankle issue, not a knee injury.
Warner's injury comes after San Francisco already lost defensive end Nick Bosa earlier in the game due to a concussion.
In the immediate aftermath of Warner going down, NFL analysts and fans alike began sending well-wishes on Twitter.
Warner has been a stalwart since entering the league in 2018. The BYU product has started 64 of a possible 65 regular season games, recording more than 115 tackles every season.
Warner was named to the Pro Bowl and All-Pro team in 2020.