Collins (hamstring) wasn't on the field during the media-access portion of Thursday's practice, Aaron Wilson of KPRC 2 Houston reports.
Wilson relays that Collins has been diagnosed with a Grade 1 hamstring strain following an MRI, with the injury putting his availability "in jeopardy" for Sunday's game against the Bengals, according to Adam Schefter of ESPN. Collins will still have one more chance to mix into drills before the end of the week, but if he isn't able to practice in some capacity Friday, the Texans could rule him out ahead of Sunday.