Watson will undergo an MRI to reveal the extent of the injury.
Watson is said to have gone down on a normal drill in which he was running the read option and he could face an eight to nine-month rehab process.
Texans quarterback Deshaun Watson's sensational rookie campaign has been cut short. McGloin is a good fit as a backup because he played for current Texans head coach Bill O'Brien at Penn State.
Watson had his best game yet in Week 8 as he dueled with Russell Wilson of the Seattle Seahawks. He saw his most National Football League action in 2013 with the Raiders when he passed for 1,547 yards, 8 touchdowns and 8 interceptions. He threw for 402 yards with 4 touchdowns, but Houston lost the game in thefinal minutes.