LAS VEGAS -- The Las Vegas Raiders fired defensive coordinator Paul Guenther on Sunday night, less than three hours after a dismal 44-27 loss to the Indianapolis Colts all but ended the Raiders' playoff hopes and dropped their record to 7-6.

It marked Las Vegas' third defeat in four games.

The team announced the move after Guenther's defense gave up 456 yards to the Colts, including 212 yards rushing. Las Vegas named first-year defensive line coach Rod Marinelli as the interim defensive coordinator to finish the season.

Raiders coach Jon Gruden was not available after Guenther was relieved of his duties, but did hint at his displeasure following Sunday's loss to Indianapolis.

"You get to the point where you second-guess everything you're doing offensively every time you punt," Gruden said, before referencing the Raiders' biggest win of the season, a victory at the Super Bowl champion Kansas City Chiefs on Oct. 11. "It's tough right now, but you have to stay confident that your players are going to put it together like they did in Kansas City.

"We struggled in the first half in Arrowhead, we found a way to make some plays in the second half. But when you can make it a one-possession game, you have to trust your defense. To be a championship team and a playoff team, you have to be a good football team in all phases."

The Raiders' defense has been anything but good this season.

Against an aging, immobile quarterback with turf toe in the Colts' Philip Rivers, the Raiders could muster only one quarterback hit, by defensive end Arden Key, while not forcing a turnover or a sack.

As noted by the Associated Press, it marked the fifth time under Guenther, who came to the Raiders with Gruden in 2018, that the team had a zero-sack, zero-takeaway game, tied for the second-most since the start of the 2018 season. The Raiders had five such games total the previous seven seasons.

In three seasons with Guenther as defensive coordinator, the Raiders ranked last in the NFL in points per game (28.4), 31st in yards per play (6.04), 29th in passer rating against (98.9), last in sacks (60) and 30th in takeaways (47).

The Raiders entered Sunday with the No. 22-ranked total defense, 24th against the pass and 19th against the run but tied for 30th in sacks with 15.

This despite adding high-profile players in free agency such as linebackers Cory Littleton and Nick Kwiatkoski, defensive tackle Maliek Collins, defensive end Carl Nassib, safety Jeff Heath and drafting cornerbacks Damon Arnette and Amik Robertson and linebacker Tanner Muse.

The Raiders also added linebacker Raekwon McMillan and pass-rushers Vic Beasley, Takkarist McKinley, Chris Smith and David Irving. None have been difference-makers.

Injuries also decimated the defense this season.

"I can't tell you one game we've had this year where somebody hasn't had to go in and play more snaps than they thought they [were going to have to] before the game," Guenther said Thursday. "So I told the guys, 'Everyone's got to prepare like they are a starting player.' You almost would rather [know] this player is not going to play this week rather than have it happen, say, in the first quarter of the game, where you've got to kind of move the chess pieces around a little bit and change your plan. So, that's probably been the most challenging thing, in-game adjustments we've had to make. Particularly the last few weeks."

Asked after Sunday's loss how tough it was to make up for defensive mistakes, Raiders quarterback Derek Carr shrugged.

"My job is to take care of the football, and my job is to move it," Carr said. "A team down the field scores touchdowns, and I didn't do that good enough today. It is what it is."