HOUSTON >> Texans quarterback Deshaun Watson sustained a season-ending knee injury in practice today, two people familiar with the situation told The Associated Press.

The rookie suffered a torn anterior cruciate ligament in one of his knees and will go on the injured reserve. The people spoke on the condition of anonymity because the team hadn’t announced the injury.

His injury is the latest blow to a team that lost three-time NFL Defensive Player of the Year J.J. Watt and linebacker Whitney Mercilus to season-ending injuries on Oct. 8.

Watson had been a relative bright spot in challenging season for the Texans (3-4). The 12th overall pick in this year’s draft was named AFC offensive player of the month after throwing for 1,171 yards with 16 touchdowns and running for 145 yards and another score.

His development this season had been a revelation for a team that has featured a revolving door at quarterback over recent years. The Texans signed Brock Osweiler to a $72 million contract before last season, but he was benched before the season was over and shipped to Cleveland in the offseason.

When Houston traded up 13 picks to take Watson, many assumed he’d be the starter to open the season. But Coach Bill O’Brien insisted he back up Tom Savage. Watson’s time as a backup was short-lived as Savage struggled in the opener and was benched at halftime, making the former Clemson standout the ninth quarterback the Texans have played in the past five years.

Watson made his first start in Week 2 and immediately excelled, leading the Texans to a 13-9 win on the road against the Bengals. Since then, he’s turned a team known for defense into one with a high-flying offense. Under his guidance, the Texans had scored 30 or more points in five straight games to set a franchise record.

Watson’s 19 touchdown passes are tried for the league lead and are the most in NFL history through a player’s first seven career games. He leads all quarterbacks this season with 21 touchdowns overall and has thrown four or more touchdown passes in three games this season to join Fran Tarkenton as the only rookies in NFL history to do so.

Now with his brilliant season cut short, the Texans will look to Savage to salvage this injury-plagued year and try to reach the playoffs for the third straight season. The Texans host the Colts (2-6) on Sunday and Indianapolis announced earlier Thursday that franchise quarterback Andrew Luck had been placed on injured reserve as he recovers from a shoulder problem that hasn’t allowed him to play at all this year.

The Texans will have to sign another quarterback to back up Savage. He is the only QB on the roster besides Watson.