Reid left in the third quarter of Sunday's 41-7 loss to the Ravens with a shoulder injury.
The concussion was just announced by the Texans on Monday afternoon. Reid's status for Thursday night's game against the Indianapolis Colts in unclear.
When asked about the status of players who were injured in the Ravens game, head coach Bill O'Brien said he was still gathering information but they appeared to be trending in the right direction.
O'Brien then met with his medical staff around 11 a.m.
If the Texans have to go without Reid, they will rely on Jahleel Addae.
Also held out of practice were safety Mike Adams (concussion) and cornerback Lonnie Johnson Jr. (ankle). Adams was injured during pre-game workouts and Johnson left the game with an ankle injury in the third quarter.
Linebacker Dylan Cole (knee), wide receiver Will Fuller V (hamstring), safety Tashaun Gipson Sr. (back), rookie offensive lineman Tytus Howard (knee) and cornerback Bradley Roby (hamstring) were all limited in practice Monday.
Deshaun Watson, who injured his ankle against the Ravens, was a full participant.
"But that's never the optimal situation," Reich said. "But he's logged enough miles and he's enough of a pro and really smart player that he's proven to be a rare exception from that standpoint."