Cincinnati Bengals quarterback Joe Burrow sat stone-faced, his left leg stretched out, as teammates and opponents congregated around the medical cart. Doctors had lifted him there after a brutal, high-low hit early in the third quarter left him screaming on the ground and holding his left knee. The entire Bengals sideline, as well as several members of the Washington Football Team, lined up to support him.

“Keep your head up,” Bengals wide receiver A.J. Green told Burrow, he said after the game.

“I love you. Get well,” said Washington defensive end Chase Young, who played with Burrow at Ohio State.

Then the cart drove off with the Bengals’ brightest hope. The sideline looked listless as Washington scored 13 unanswered points, eventually winning 20-9. For Cincinnati, the loss of Burrow hurt far worse than that of the game. In Coach Zac Taylor’s second season, the team is floundering at 2-7-1 and now is without its franchise quarterback for the foreseeable future.

Burrow tore the ACL and MCL in his left knee, according to multiple reports on Monday, and will undergo reconstructive surgery and rehab in hopes of returning at the beginning of next season.

“Thanks for all the love,” Burrow wrote on Twitter shortly before the end of Sunday’s game. “Can’t get rid of me that easy. See ya next year.” He added a fist emoji.

The offensive rookie of the year favorite was the latest injury in a brutal year for quarterbacks. Four starters are on injured reserve, and three more — Sam Darnold, Teddy Bridgewater and Gardner Minshew II — missed Week 11 with various injuries. At FedEx Field, Burrow was the third passer to suffer a serious injury in the last month alone, joining Washington’s Kyle Allen (ankle) and the Dallas Cowboys’ Andy Dalton (concussion).

For Alex Smith, the quarterback who beat the Bengals, it was his first win since he suffered a gruesome right leg injury on this field two Novembers ago. Smith was the No. 1 overall pick 15 years before Burrow, and their continued parallels Sunday did not escape his notice. He said he never liked to see the medical cart come out.

“Big fan of his game,” Smith added. “The way he was playing this year . . . I remember how hard it was as a rookie to play, and certainly as well as he is playing, you hate to see this.”

After the game, Taylor maintained he couldn’t have done anything different to better protect Burrow on the play.

“When he made that throw, he was clean [in the pocket],” Taylor said.

On replay, the hit looked unavoidable. Three things happened at the same time.

Burrow stepped up to throw, leaving his left leg vulnerable. Meanwhile, Cincinnati left guard Michael Jordan pushed bull-rushing defensive tackle Jonathan Allen into Burrow’s legs as defensive end Montez Sweat hit Burrow high. The combination of the two hits at once perhaps prevented Burrow from falling backward and instead put the pressure on Burrow’s left knee, which folded in.

The Bengals have struggled to protect Burrow all year. Entering Sunday, he had taken 72 hits, according to Sportradar, tied with the New York Giants’ Daniel Jones for the most by a quarterback in his first nine games since at least 2000. This in part because of instability on the offensive line — Sunday marked Cincinnati’s sixth different starting unit in 10 games — but Taylor bristled at the suggestion the line was to blame.

“People keep talking about the offensive line without seemingly watching the film the last four weeks,” he said, adding: “We felt like we were making a lot of progress over the last five weeks, and we are not going to apologize for any of that.”

After the injury, players “were a little shook, to be honest,” Bengals backup quarterback Ryan Finley said. Players and coaches acknowledged the game’s tone shifted after the injury, and Washington capitalized in the win.

The support shown for Burrow extended to social media, with messages from the likes of star quarterbacks Patrick Mahomes and Russell Wilson. Washington Coach Ron Rivera began his postgame news conference by praising Burrow as “a heck of a young man and a heck of a football player.” Washington was particularly affected by Burrow’s injury because three players — wide receiver Terry McLaurin, quarterback Dwayne Haskins and Young — played with Burrow at Ohio State before he transferred to LSU.

“I wanted to keep playing against Joe,” said Young, who forced a fumble by Burrow on a crushing hit earlier in the game. “I was hurting for Joe. You just never want to see that happen to anybody.”

For Cincinnati, the injury asks a franchise and fan base for patience at a time when they might not want to give it. The star Burrow was becoming buoyed hope that, 30 years since the Bengals’ last playoff win, they might capture another one in the near future. They must rely on the rookie approaching the injury as he has everything else.

“He handled everything like a professional from day one,” Taylor said. “The players have responded to him; the coaches have responded to him; the city has responded to him; and all that is equally as important. Everything we’d hoped he would be, and we’ll get him back at some point.”