From the video

Video: Top 50 Week 9 Running Back Rankings + Tiers
No Trevon Henderson. I would expect Trevon Henderson to maybe not play for the rest of the season. And there's some weird stuff going on. No, weird just like non-defined things going on with Trevan Henderson. He is both listed with an injury and an illness. And apparently the illness is like a mental health thing.
Mentioned at 4:15 – 5:01Captured by STACKED 47 min after posting

STACKED’s take

Negative signalInjury

Expected out for rest of season with injury and mental health illness.

Source expects Trevon Henderson to maybe not play for the rest of the season; he is listed with both an injury and an illness (mental health related). The source notes this is a difficult situation for elite athletes when their ability to play is taken away or when they're in an unfamiliar depth chart position.

TreVeyon Henderson headshotTreVeyon HendersonRB · NEPlayer page — value, ADP, projections, and every insight