Jackson suffered a concussion on the final play of the third quarter, when his head snapped back and hit the turf in the end zone at Bills Stadium. He was later ruled out for the entire fourth quarter for the Ravens, who haven't advanced past the divisional round since the Mile High Miracle eight years ago.
Afterward, Jackson was cleared to return home on the team flight, a source told ESPN.
"He's frustrated. He's doing good," said Baltimore wide receiver Willie Snead IV, who spoke to Jackson following the contest. "He said he's fine from the concussion but he's frustrated that we were that close and that we didn't get to finish drives. He's the ultimate competitor. He doesn't like to lose."
Ravens coach John Harbaugh declined to elaborate on Jackson's status.
"He was ruled out with a concussion, and that's where it stands," Harbaugh said.
A week after capturing his first postseason win, Jackson failed to produce a touchdown for the first time since his first NFL start in November 2018. His streak of 39 straight games with at least one touchdown, run or pass, had been the longest active one in the league.
Jackson's head injury came two plays after he threw the second pick-six of his career. Driving down to the Buffalo 9-yard line, Jackson stared down tight end Mark Andrews and was picked off in the red zone for the first time in his 41-start career.
Bills cornerback Taron Johnson outran Jackson and returned the interception 101 yards for the score. Instead of potentially tying the game at 10, the Ravens fell behind by two touchdowns.
Snead said the Ravens heard all week on social media how Jackson had thrown 49 touchdowns and no interceptions inside the 20-yard line.
"That kind of jinxed us right there," Snead said with a laugh. "[Johnson] just squeezed real hard on Mark, and [Jackson] didn't see him. It's just one of those plays where he threw it and [Johnson] jumped it. It just sucks. It was a huge momentum shift in the game."
Jackson was harassed throughout the game by the Bills and had to constantly elude pass-rushers in the pocket. He got pressured on 55% of his dropbacks, the highest rate of his career.
On the final play of the third quarter, Jackson chased down a snap that sailed over his head and threw the ball away before being taken down to the ground. Buffalo linebacker Tremaine Edmunds wrapped up Jackson's legs, and defensive end Trent Murphy hammered Jackson high, driving him onto his back.
Asked if the wind gusts affected the errant snaps by Ravens center Patrick Mekari, Harbaugh said, "I'm sure the wind was part of that, and I'm sure there were other issues too that I'm not sure if I can comment on at this time. I was on the sideline; I wasn't out there [on the field]."
As soon as the back of Jackson's head bounced off the turf, he immediately grabbed his helmet with both hands. He then threw his hands up in disgust while walking to the locker room with a trainer.
"He's a tough guy," Andrews said. "So anytime you see him go down, you know he's feeling something."
It is believed to be only the second time Jackson was put in the concussion protocol. In his third start (December 2018), Jackson was examined after his head accidentally hit the foot of left tackle Ronnie Stanley at the Atlanta Falcons but later returned to the game.
On Saturday night, Jackson never came back from the locker room, marking only the second time he was unable to finish a game due to injury.
"It's just a sucky moment," Snead said. "Just the competitor he is, I know he just wants to be out there and finish the game for us and give us a chance to come back."
Like Jackson's previous playoff losses in 2018 and 2019, the Ravens struggled offensively, this time tying a franchise record for fewest points in a playoff game. Baltimore lost at the Indianapolis Colts 20-3 in the 2009 AFC divisional round.
Jackson was held to 14-of-24 passing for 162 yards, which will put even more pressure on him to develop as a passer next season.
"He'll look back at the whole season and he'll make those adjustments that he needs to do to be an even more elite quarterback," Snead said. "There are steps that he can take, and he knows that. That's the competitor in him to want to get better each and every offseason, to fix the little things and to continue to get better as a passer.
"If he knuckles down on that part of his game and really reaches his full potential in that area, the sky is the limit for Lamar. It's just a matter of time. It's really on him. I think this game is going to be a wake-up call for him this offseason. We'll see what he does next year."