Raiders fire defensive coordinator Paul Guenther

FILE - In this April 11, 2019, file photo, Oakland Raiders defensive coordinator Paul Guenther attends an NFL local Pro Day at the team's football facility in Alameda, Calif. The Las Vegas Raiders fired Guenther after he failed to make any significant improvement for the unit in nearly three full seasons on the job. (AP Photo/Jeff Chiu, File)
FILE - In this April 11, 2019, file photo, Oakland Raiders defensive coordinator Paul Guenther attends an NFL local Pro Day at the team's football facility in Alameda, Calif. The Las Vegas Raiders fired Guenther after he failed to make any significant improvement for the unit in nearly three full seasons on the job. (AP Photo/Jeff Chiu, File) (Copyright 2019 The Associated Press. All rights reserved.)

The Las Vegas Raiders fired defensive coordinator Paul Guenther after he failed to make any significant improvement for the unit in nearly three full seasons on the job.

The Raiders (7-6) announced the decision Sunday following a 44-27 loss to the Indianapolis Colts that dealt a severe blow to their playoff chances. Defensive line coach Rod Marinelli will take over on an interim basis for the rest of the season.

The Raiders allowed 212 yards rushing, 7.7 yards per play, had no sacks, no takeaways and forced only one punt in a game that was all too reminiscent of so many since Guenther arrived with coach Jon Gruden in 2018.

“No answer today, but we better find some answers and as soon as I’m done here, we’ll start searching,” Gruden said after the game but before the decision was announced.

Guenther was Gruden’s most important hire when he returned to the Raiders in 2018, but he was never able to rebuild a defense that was gutted when star pass rusher Khalil Mack was traded to Chicago before the season opener that year.

In nearly three full seasons with Guenther running the defense, the Raiders ranked last in points allowed per game (28.4), last in sacks (60), 31st in yards per play allowed (6.04), 30th in takeaways (47) and 29th in passer rating against (29th).

But the biggest issue was that the team showed few signs of improvement this season despite having made heavy investments in free agency and with four defensive starters drafted in the top two rounds the past two seasons.

The Raiders showed some flashes earlier in the season, slowing Patrick Mahomes down in the second half of an upset in Kansas City in October and then generating five takeaways in a win over Denver last month.