Last year on Christmas Eve, NFL fans were dealt a cruel blow when Derek Carr and Marcus Mariota, two of the best young quarterbacks in the game, suffered injuries on the same day. On Sunday in Week 4 it happened again. 

In 2016, both Carr and Mariota suffered broken legs during their Week 16 games, with Carr's injury setting up a Connor Cook playoff start (the Raiders would lose to the Texans) and Mariota's injury ending the Titans' playoff hopes (Matt Cassel couldn't elevate the offense). In 2017, the injuries were different but just as concerning. 

Mariota suffered a hamstring injury in a blowout loss to the Texans and is set for an MRI to determine the severity. Hamstring injuries can linger, so it wouldn't be surprising to see Mariota miss time.

Carr's injury, which happened on a sack against the Broncos, is even more concerning because of how awkward it looked again and because we're still getting more info on the extent of what happened.

With the Broncos pressuring him, Carr took off running and was spinning to avoid contact when Shelby Miller came in to tackle him and accidentally put a knee in Carr's back. Carr remained on the field holding his back and appearing to be in severe pain.

"NFL on CBS" analyst Tony Romo, himself no stranger to back issues, sounded extremely concerned about the injury, noting with Jim Nantz that twisting the back as he's being kneed can increase the pain and injury risk.

"It's the twisting and then getting kneed at the same time," Romo said on the broadcast. "It's your back getting twisted. It's just a huge blow to this Oakland team." 

The good news is that Carr was able to walk to the blue medical tent and was listed as questionable to return. After the game, coach Jack Del Rio said that the injury was just back spasms, which seems like a best-case scenario after how the injury looked in real time.

If Carr can't play moving forward, the Raiders will have to lean on EJ Manuel, the former first-round pick of the Bills who signed this offseason to be the backup. They're not confident about it, and if you don't believe me, just ask Del Rio. With the Raiders deep in their own territory, punter Marquette King ran a fake punt that came up short and actually resulted in a taunting penalty against the punter when he threw the ball at a Broncos player afterwards. 

It's possible that King went rogue on the play and ran it himself, but regardless, there was clearly an impetus on trying to generate some free possession time for the Raiders with Manuel under center.

This is a very different Oakland team with Carr not on the field. Raiders fans should be holding their breath as they monitor his status throughout the week.