Watson will undergo an MRI to reveal the extent of the injury.
The injury is awful news for the Texans, whose offense was thriving with Watson at quarterback. The wording from Rapoport leaves open the smallest window for optimism, but if the Texans' worries are confirmed, Watson would surely be out for the year.
Texans quarterback Deshaun Watson's sensational rookie campaign has been cut short.More news: India To Observe 'Anti-Black Money Day' On November 8!
The injury reportedly happened on a non-contact play during the team's workout.
Watson passed for 1,699 yards over six games and is tied for the National Football League lead in passing touchdowns with 19. He has also added 269 rushing yards and two rushing touchdowns. He passed for 402 yards and four touchdowns in the Texans' 41-38 loss to the Seattle Seahawks in one of the most exciting games of the season.
Along with Barry Sanders, Edgerrin James, Mike Anderson and Kareem Hunt, Watson is among the only rookies to win the Offensive Player of the Month honor. Tom Savage, who finished Thursday's practice with the top unit, will start in Watson's absence moving forward.
Watson completed 77 of 124 passes for 1,171 yards with 16 touchdowns and five interceptions in four games last month.