ALLEN PARK, Mich. -- Detroit Lions defensive coordinator Paul Pasqualoni stepped down Thursday after coaching one of the NFLs worst defenses throughout the 2019 season.

Pasqualoni, 70, was one of the first hires made by Lions coach Matt Patricia in February 2018.

Pasqualoni and offensive line coach Jeff Davidson, who also stepped down Thursday, created the seventh and eighth vacancies on the staff since the season ended Sunday. Six coaches -- including special-teams coordinator John Bonamego and the Lions' two main strength and conditioning coaches -- were fired Tuesday.

Detroit now has to replace its defensive coordinator, special-teams coordinator, tight ends coach, offensive line coach, linebackers coach, defensive backs coach and the strength staff. Of Patricia's original staff, only defensive line coach Bo Davis and receivers coach Robert Prince remain.

The Lions said Pasqualoni is resigning to be closer to his family and Davidson is taking "an indefinite leave from coaching" and has left open the possibility of returning to coaching in the future.

"Coach P is one of the best men I've ever been around, on both personal and professional levels," Patricia said in a statement. "I owe him so much and I'm grateful of the impact he had on our players, coaches and support staff.

"He will continue to be a great sounding board for me as a coach, father and leader."

On Monday, at his season-ending news conference, Patricia wouldn't say whether he would make changes to his coaching staff after compiling a 9-22-1 record in two seasons.

Pasqualoni's job status had been in question for weeks as Detroit's defense continued to falter and languish in the bottom of the league rankings. For most of November, Patricia answered questions about whether Pasqualoni was still calling plays and often gave vague answers.

The Lions ranked No. 31 in yards allowed per game (400.4), No. 32 in passing yards allowed per game (284.4) and No. 21 in rushing yards allowed per game (115.9). They compiled a league-worst 1.1% interception rate and sacked quarterbacks on 4.6% of their dropbacks, No. 31 in the league. They also allowed 26.44 points per game, which ranked 26th in the NFL.

In Week 12 against Washington, Patricia was spotted during many defensive plays with the laminated play sheet covering his mouth while he was talking into the microphone. Pasqualoni, meanwhile, was often silent during the times when defensive calls would be relayed in.

After the 19-16 loss to Washington, Patricia still wouldn't say who was making the defensive decisions, declining to get into any specifics. When asked about the play sheet, he said he's communicating through four lines with different people he's talking to.

"I have a lot of different roles on game day," Patricia said. "Certainly from that standpoint, I'm very active in the communication from all phases of the game, all three phases, and so there's going to be plays out there that I can call. There's going to be plays out [Pasqualoni] is calling. There's going to be plays out there that certainly are just automatic for us."

On Monday, Patricia declined to answer whether he would be calling Detroit's defensive plays in 2020.