Perhaps the biggest domino of the Dallas Cowboys' offseason dropped Thursday afternoon.

Defensive coordinator Dan Quinn, after interviewing for three head-coach openings, will return to Dallas for a third season, head coach Mike McCarthy confirmed to Dallas reporters.

“We’re all extremely excited to have Dan back,” McCarthy said, per ESPN’s Todd Archer. “Had a chance to visit with him a short while ago. This is big for us. Gives us continuity. Definitely what we’ve accomplished the last two years, building off of that.

“Frankly, on a personal note, I can’t tell you how thankful I am.”

Quinn interviewed for the head-coaching vacancies of the Denver Broncos, Arizona Cardinals and Indianapolis Colts. The Cowboys sought his return, though NFL teams cannot block moves to another franchise that qualify as a promotion.

McCarthy credited staff and player relationships as reasons he thinks Quinn chose to return to the Cowboys before the positions were filled. Dallas’ progress, relative to the state of the franchises with which Quinn interviewed, might've factored in as well.

Quinn’s next opportunity will be his second as head coach after he led the Atlanta Falcons from 2015 until midway through 2020, advancing to the Super Bowl in the 2016 season.

“He understands at this point of his life how hard it is to win a Super Bowl,” McCarthy said of Quinn. “So I think all of those things play into that. I think clearly Dan is in a position to be selective. And I’m extremely excited about the decision.”

Quinn spearheaded a Cowboys defense that led the league in takeaways for consecutive seasons, making it the first unit to retain that crown since the Pittsburgh Steelers in the 1970s.

The Cowboys ranked fifth in points allowed in 2021, Quinn's inaugural season, after ranking seventh in 2020. Compare that with the last season before Quinn arrived, when Dallas’ 2019 unit ranked 28th.

Quinn has overseen the breakout of players including two-time All-Pro Micah Parsons, whom he creatively schemed as an off-ball linebacker and increasingly at edge rusher. He has encouraged versatility from his defensive backs, too, including veteran safety Jayron Kearse, who has matched up on tight ends akin to a linebacker.

“Part of the player I am now is because of coach Quinn giving me the opportunity,” Kearse said earlier this month. “There's not anything he thinks I can’t do, not anything he won’t do to put me in positions to go out there and play at a high level.

"One of those coaches who guys in this locker room would run through a wall for. … He’s been heaven-sent for me."

In their divisional-round loss to the San Francisco 49ers, the Cowboys held the 49ers to 19 points. Quarterback Brock Purdy said this week that Dallas had “one of the best defenses” the 49ers had seen this season.

McCarthy said Thursday that Cowboys team owner Jerry Jones told him this week that he hoped McCarthy could coach as long as franchise legend Tom Landry.

McCarthy declined to give the same vote of confidence to offensive coordinator Kellen Moore when asked.

But one major coaching decision appears to be set. And the Cowboys' defensive players will undoubtedly celebrate it.