Not because of aftershocks from the concussion he suffered in the Chargers' stunning 31-30 loss to Denver Nov. 1, one of many heartbreaking, one-score losses the Chargers have suffered. Those were bad enough that he wore special glasses to block out the sunlight.
No, these were aftershocks from the best game he played all season -- a career-high three sacks, six total tackles for loss, five quarterback hits, a pass defensed and a fumble recovery. Bosa was the first to record such a stat line since tackles for loss were first tracked in 2008.
He became one of three players in NFL history to record three sacks, five QB hits, a pass breakup and a fumble recovery in the same game, joining James Harrison (2007) and Justin Houston (2013).
But Bosa's heroics weren't enough to get the victory, as the Chargers fell 27-17 to the Buffalo Bills to drop to 3-8 on the season. That record -- not his historic day and not passing Hall of Famer Junior Seau for fifth on the Chargers' all-time sack list with 47.5 -- is what was eating at him in his postgame Zoom interview. He twitched, he stretched, he looked agitated even as he politely answered questions from reporters.
"It sucks," he said simply.
And he knew the nearly five-hour flight back to Los Angeles was going to be even worse and then some.
"I know I'm going to wake up tomorrow and feel like s---," he said. But he also said being miserable is not an option, nor is it for his team, which has lost seven one-score games this season and lost four times after holding a double-digit lead.
"Not gonna happen on my watch," he added.
"He works hard," Chargers coach Anthony Lynn said. "Joey was playing early on with 2-3 different injuries we didn't even know about. He was playing through it, wants to be out there with his teammates and help us win. I love how professional he is; he gets his body right and gets back out there. He makes a difference."
That responsibility a lot to lay on a 25-year-old out of Ohio State, who has 7.5 sacks, 14 tackles for loss and 23 QB hits in nine games. Bosa was the third overall pick in the 2016 draft and was named AP defensive rookie of the year that season.
He has been a bright spot on a defense in sore need of one. And he's been a bright spot for his 23-year-old brother, Nick, who tore his ACL in week two this season after a banner rookie season of his own in 2019 after being drafted No. 2 overall by the San Francisco 49ers. Nick Bosa has been bunking at Joey's Orange County home with frequent visits from Mom, Cheryl, and Dad, John -- a first-round draft pick by the Dolphins in 1987 -- complete with home cooking.
But this week is different. This week is hard. Especially with Pro Bowl teammate Melvin Ingram III out with a knee injury. The two make up a dynamic force, but have only been on the field together in five games this season.
"I really, really wanted to pull that one out," Joey Bosa said of the Buffalo loss. It's just hard to feel excited about a tough game like that."
Bosa said he thought the game would turn once the defense forced three turnovers in seven minutes spanning the end of the third quarter and start of the fourth. But the Chargers were only able to get three points off those takeaways.
"Everyone is pretty upset," he said. "We knew it was a big game if we were to make a big push at the end of the season."
Bosa signed a five-year, $135 million contract extension over the summer after recording 19 sacks in his first 20 career games. Life is not so tough.
If only the Chargers could win.
"We can't be depressed, hang your head," he said. "It should hurt, it should suck. But guys aren't going to mope around ... we will pull together ... It could be a long rest of the season of guys start shutting down."
With a home game against the New England Patriots next (4:25 p.m. ET Sunday, CBS) followed by games at home against the Atlanta Falcons, at Las Vegas, at home against the Denver Broncos and at the Kansas City Chiefs, they can't afford to shut down. Bosa said he won't allow it.
"It starts with me having a good attitude tomorrow," he said on Sunday.
After a long plane ride home to mull everything over.