Collins (calf) wasn't present for Friday's practice, DJ Bien-Aime of ESPN.com reports.
Given that Collins didn't practice Wednesday or Thursday, the wideout doesn't seem likely to suit up Sunday against the Titans. If Collins is out this weekend, Noah Brown (knee) and Robert Woods would be in line to lead the Texans' Week 15 WR corps, with Xavier Hutchinson and John Metchie also likely to see added opportunities this weekend.