Ogletree intercepted a pass and returned it 41 yards for a touchdown, flipping into the end zone.
Alden Gonzalez of ESPN didn't believe the linebacker hurt himself in the celebration, although it's unclear when he picked up the injury.
Durability has been a defining factor in Ogletree's career outside the 2015 season, so this injury is a difficult blow for Los Angeles. He played all 16 games in his three other campaigns and developed into one of the team's most reliable defenders, although he played just four contests in 2015 because of an ankle setback.
When healthy, Ogletree's speed and athleticism at the position jump out, and he can pursue a running back across the field or stick with tight ends or backs in pass coverage. What's more, he is versatile enough to plug holes in the middle or attack the passer off the edge and tallied a career-best 136 combined tackles last year.
He had 76 tackles entering the day with two sacks.
If Ogletree is forced to miss extensive time, others will have to fill the void and keep the Rams defense afloat.
Bryce Hager can pursue ball-carriers on the outside or stick with pass-catchers in coverage. Los Angeles also has veteran Mark Barron at its disposal.
They may not be the proven commodity that Ogletree is, but the Rams need them to shoulder the load until the starter returns.