Redskins quarterback Alex Smith broke his right tibia and fibula against the Texans on Sunday and will require immediate surgery, head coach Jay Gruden told reporters after the game.

Smith was carted off the field during the third quarter, his right lower leg in an air cast, after being sacked by J.J. Watt and Kareem Jackson. His right foot got caught underneath him and bent awkwardly. He remained down for several minutes before being carted off the field.

Former Redskins quarterback Joe Theismann, whose career ended with a broken leg during a game in 1985, tweeted: “I feel so bad for him.”

“Alex’s leg is exactly like mine 33 yrs ago,” Theismann wrote.

The team announced shortly afterward that Smith would not return, calling it an ankle injury. Smith went 12-of-27 passing for 135 yards and two interceptions, including a pick-six, before departing. Colt McCoy replaced Smith at quarterback, throwing a touchdown to Jordan Reed on his first attempt to cut Washington’s deficit to 17-14 late in the third quarter.

Washington took a 21-20 lead early in the fourth quarter on a touchdown run by Adrian Peterson, but the Texans rallied for a 23-21 victory. McCoy finished 6-of-12 passing for 54 yards and a touchdown, while also rushing for 35 yards on five carries.

Watt expressed on Twitter how badly he felt about the injury and sent his support and well wishes to Smith.

“Thoughts are with Alex,” he wrote. “Absolutely gutted about it. Never want to see that for anyone ever. Wishing you all the best brother.”

Smith, 34, arrived in Washington D.C. via trade this offseason from the Chiefs, where he started 76 games over five seasons. He signed a four-year, $94 million contract with the Redskins shortly after the trade. Entering Sunday, McCoy had not attempted a pass since the 2015 season. He hasn’t started a game since 2014, his first year in Washington.