One of the most promising NFL seasons by a rookie quarterback came to an end on Sunday.

Cincinnati Bengals quarterback Joe Burrow effectively ruled himself out for the remainder of the 2020 season after he was carted off the field in Sunday's game against the Washington Football Team. Burrow suffered a left-leg injury in the third quarter. Burrow was sandwiched by two Washington defenders who converged on him on a third-and-2 pass attempt.

On Sunday afternoon, Burrow sent out a tweet thanking people for support and suggesting he was done in 2020. "Thanks for all the love," Burrow said. "Can't get rid of me that easy. See ya next year."

The first overall pick in the 2020 draft was on pace to become the first rookie in league history to have six 300-yard passing games in his first 10 games. Instead, the future of Burrow's rookie season is now in question after the injury. Burrow was 22-of-34 passing for 203 yards, one touchdown and one lost fumble before he went down in the third quarter.

After he threw a pass intended for Bengals receiver Tyler Boyd, Washington defensive linemen Jonathan Allen and Montez Sweat hit Burrow from opposite sides. Allen beat a block on Burrow's left, while Allen came off the right edge to hit Burrow. Almost immediately, Burrow clutched his left leg as Bengals coach Zac Taylor came out to check on the franchise's star quarterback.

As Burrow was being carted off, the entire Bengals sideline approached the quarterback to encourage him. Well-wishers also included Washington's Chase Young, Terry McLaurin and Dwayne Haskins, who all played with Burrow at Ohio State before he transferred to LSU and eventually led the Tigers to a national title.

Burrow was quickly ruled out of the game and replaced by second-year quarterback Ryan Finley.

Cincinnati had hoped Burrow was the franchise's next cornerstone quarterback when the Bengals selected the southeast Ohio product with the top overall pick in April's draft. Almost as soon as Burrow officially arrived in Cincinnati, it was clear he was going to be the team's Week 1 starter as a rookie. The Bengals released veteran Andy Dalton, the team's second-round pick in the 2011 draft, and didn't add another veteran quarterback to the 53-man roster.

In his first 10 games, the rookie showed why he represents so much hope for a franchise that hasn't won a playoff game since January 1991. According to ESPN Stats & Information, Burrow ranks fourth in NFL history for the most passing yards in a player's first 10 games (2,688 yards, including his total from Sunday's game). In a Week 7 loss to Cleveland, Burrow threw for a season-high 406 yards, matching Andrew Luck's 2012 record for the most 300-yard passing games during a rookie season (six).

Cincinnati's ability to protect Burrow was one of the biggest questions entering the 2020 season. Entering Sunday, Cincinnati ranked 28th in the NFL in pass-block win rate, an ESPN metric powered by NFL Next Gen.

If Burrow is out for an extended period of time, it will delay Cincinnati's rebuilding project that is centered on the rookie quarterback. He could also become the first top-overall-pick rookie to suffer a serious injury since Jadeveon Clowney, who played four games in 2014 before he had microfracture surgery to repair his right knee.