Redskins quarterback Alex Smith will miss the rest of the season after breaking two bones in his right leg during Washington’s 23-21 loss to Houston on Sunday.

Smith fractured tibia and fibula bones on a sack by Texans defensive back Kareem Jackson midway through the third quarter. His distress was evident immediately; he glanced at his leg, its lower half and ankle bending in the wrong direction, and immediately threw off his helmet and put his hands over his face before he was attended to by trainers, who carted him from the field.

The team quickly announced that Smith was out with an ankle injury, and Coach Jay Gruden said after the game that Smith will require surgery, confirming he will miss the remainder of the year. He left FedEx Field via ambulance; CBS reported he was taken to Prince George’s Hospital Center.

Smith had led the team to a 6-3 record and entered the game with 2,045 passing yards, 10 touchdowns and three interceptions.

“I played with him so long, he’s like a brother,” said tight end Vernon Davis, who played with Smith in San Francisco. “To see him go down and suffer is like, ‘Why not me?’ Maybe I should suffer and let him continue to go out there and do his job and help this team win. Because I know how bad he wants it. I know how much work he’s put in. Starting from San Francisco, going to Kansas City. He’s worked extremely hard. He’s resilient. He’s the most resilient person I’ve ever met. He’s been through so much.

The Redskins traded a third-round pick and cornerback Kendall Fuller to the Chiefs for Smith during the offseason. The organization then signed him to a four-year, $94 million extension.

“Now it becomes a situation where, of course we’re playing for each other, but we’re also playing for Alex,” Davis said.

The injury drew comparisons to the broken leg that Redskins quarterback Joe Theismann suffered in 1985. Theismann, at FedEx Field on Sunday, tweeted, “Alex’s leg is exactly like mine 33 yrs ago.”

Theismann’s injury also took place on Nov. 18 and, in yet another eerie similarity, the final score of that Monday night game against the New York Giants was also 23-21 (though the Redskins won).

The Redskins trailed 17-7 at the time of Smith’s injury. Backup quarterback Colt McCoy replaced Smith and led a comeback effort that fell two points short. Smith threw two interceptions against the Texans.

Teammates and officials urgently signaled for the medical staff after Smith went down. It typically takes some time for a decision to be made on whether the cart will be necessary to transport an injured player off the field, but that was not the case Sunday for Smith.

“I know it was very painful for him and heartbreaking for a lot of people,” Coach Jay Gruden said. “He’s a great guy and a hard worker and one of the key leaders on this football team. These things happen in pro football, unfortunately. You just hate to see them happen to a guy like Alex.”

Teammates were visibly shaken and players emptied the bench to give words of encouragement to Smith while he sat on the cart. Most of the Texans also left the bench to acknowledge their opponent. Smith waved to the crowd, placed his hand over his heart and made a praying-hands gesture to the stands as he rolled into the tunnel.

Running back Adrian Peterson, who has suffered season-ending ACL and neck injuries during his career, sympathized.

“He has to accept it for what it is and get his mind wrapped around it and look toward the recovery,” said Peterson, a few feet from Smith when he was hit. The veteran running back knew immediately Smith’s season would be over. “That has always been my No. 1 approach to those types of injuries. It’s all about how your respond individually and the mind-set that you have going in to attack that type of recovery. He’s going to have our support and our prayers go out to him and his family.”

Colt McCoy is the only other quarterback on the roster and he quickly entered the game and threw a nine-yard touchdown to tight end Jordan Reed on the second play from scrimmage. He led another scoring drive to give Washington a brief 21-20 lead. McCoy completed 6 of 12 passes for 54 yards and a touchdown. He also ran for 35 yards on five carries.

“I’ve been places where if the quarterback goes down,” guard Tony Bergstrom said, “it’s like, shoot, might as well start trying for a draft pick. But we’re in a spot where you couldn’t ask for someone better to be out there. Colt would be starting in any other system.

“I don’t think there’s any change. Colt can do all the same things.”

The Redskins will work out Mark Sanchez, T.J. Yates and E.J. Manuel on Monday, a person familiar with the team’s front office decisions said.

Sanchez last played in 2016 as a member of the Dallas Cowboys and signed a one-year deal in 2017 with the Chicago Bears, in part, to help mentor Mitchell Trubisky. He was a four-year starter for the Jets after being selected No. 5 overall in 2009.

Yates started three games for the Texans last season, but has never been a full-time starter in the NFL. His best season came as a rookie in 2011 when he threw for 949 yards with three touchdowns and three interceptions in six games.

Manuel played two games with the Oakland Raiders last season after a tumultuous four years in Buffalo after being the No. 16 overall pick in 2013. He was cut by the Raiders in September. Manuel threw for 1,972 yards with 11 touchdowns and nine interceptions as a 10-game starter in 2013.

And any time a quarterback vacancy arises, former 49ers quarterback Colin Kaepernick’s name is discussed. He last played a game in 2016 and many believe Kaepernick has been blackballed from the league for kneeling during the national anthem and speaking out against police brutality and racial inequality.

“It’s probably going to be less workout related,” Gruden said. “Maybe more . . . familiarity with either [offensive coordinator Matt] Cavanaugh or [passing game coordinator Kevin] O’Connell, maybe. We’ll see. We’ll take a look at the names, all talk about them and go from there.”