Since Bill Belichick became coach of the New England Patriots in 2000, he has seen multiple assistants leave for other jobs.
This year will be no different as defensive coordinator Matt Patricia and offensive coordinator Josh McDaniels are expected to become NFL head coaches.
Though his defense was torched by Nick Foles and the Philadelphia Eagles in Sunday's 41-33 Super Bowl loss, Patricia will take over the Detroit Lions. McDaniels will become the Indianapolis Colts' new coach.
And yet don't expect much to change for the Patriots, who were denied a sixth Super Bowl title but are favourites to be back next season. Despite the consistent turnover on his staff, Belichick is the one constant.
"It's very impressive what they've done, continue to accomplish," Green Bay Packers quarterback Aaron Rodgers told Omnisport. "They get guys to buy into what they're doing, get them to fall in line, and they win. That's what they do. It's impressive to watch because you know how difficult it is to get there."
-- OptaJerry (@OptaJerry) February 5, 2018
McDaniels will be leaving the Patriots for a second time. He was their offensive coordinator from 2006-08 before becoming the Denver Broncos head coach in 2009 and eventually returning to New England in 2012.
"He's a great coach. Any team would want him to be the leader of the organisation," Pats quarterback Tom Brady said of McDaniels.
As mentioned, McDaniels and Patricia are not the first coordinators to move on from New England -- and they likely won't be the last.
Former offensive coordinators Charlie Weis and Bill O'Brien left to become college head coaches. O'Brien parlayed his job at Penn State into becoming the head coach of the Houston Texans.
Romeo Crennel and Eric Mangini, both former Patriots defensive coordinators, also left to take head coaching jobs.
Belichick's coaching tree is extensive and will continue to grow as long as he remains the Patriots coach. How long might that be? At 65, he is likely tied at the hip with Brady, 40, who was the NFL MVP in 2017 after leading the league with 4,577 passing yards.
Without Brady, Belichick might not have had the same success -- and vice versa. Despite Sunday's loss to the Eagles, neither has anything left to prove after winning five Super Bowls together in eight appearances over the last 18 years.
"The guy is literally what everyone is striving to be when it comes to longevity," Washington Redskins quarterback Alex Smith told NFL Network.
As for Brady, who will turn 41 a month before beginning his 19th NFL season, history is not on his side. He takes care of his body better than most players and says he wants to play until he's 45, but Father Time is undefeated.
When asked about his future during Super Bowl week, Brady just laughed it off and said he'll play as long as he can.
LET'S GOOOOOOO. pic.twitter.com/C3fYNhytB0-- New England Patriots (@Patriots) February 4, 2018
"Why does everyone want me to retire so bad?" he said. "I don't get it. I'm having fun. The team's doing good. I know I'm a little bit older than most of the guys, but I'm really enjoying it.
"Obviously, I enjoy the experience of playing in this game. This has been obviously a dream come true many times over. It takes a lot of hard work to get here, and I think our team is working hard.
"So I'm not thinking about retirement.
"I've always wanted to play to my mid-40s, so we'll see," he added. "Football is such a physical sport. Every game could be your last game, that's the reality of the sport."
Brady is a sure-fire Hall of Famer, but previous quarterback inductees like Brett Favre and Warren Moon saw significant drop-offs in their play the season after turning 41.
Whether that happens with Brady remains to be seen, but it's probably a bad idea to bet against him.