Los Angeles Rams head coach Sean McVay told reporters defensive tackle Aaron Donald suffered an ankle sprain during Sunday's loss to the Kansas City Chiefs.
Donald is undergoing testing to determine the severity of the setback.
The 31-year-old rarely misses any time because of injury, appearing in 127 of 129 possible regular-season games over his first eight years in the NFL. He made 65 straight regular-season starts from 2018 to '21.
Donald has also been a key contributor in the playoffs, tallying 3.5 sacks across four postseason games last year while helping the Rams win the Super Bowl.
The championship added to a resume of someone who was already one of the top defensive players of his era. The Pittsburgh product earned a Pro Bowl selection in each of his first eight years in the league and was named first-team All-Pro for the seventh straight time in 2021.
Donald has been named Defensive Player of the Year three times and was a top contender for the award again in 2021 after totaling 12.5 sacks and a career-high 84 tackles.
This is shaping up to be a lost season for the 3-8 Rams, and missing Donald for the upcoming contest against the Seattle Seahawks would be yet another obstacle to overcome.