The San Antonio Spurs has always been a franchise built on stability and one man who has been hugely responsible for developing and maintaining that culture is head coach Gregg Popovich. 

The 69-year-old has been in charge for 22 years and has played a major role in making the Spurs one of the best organisations in sports. 

They have been the epitome of success both on and off the court and have coach Pop to thank for that. 

But the experienced coach will not be around forever and every great era must one day come to an end. 

Retirement

The end could well be in sight for Popovich as he has reportedly decided when he wants to bring his long tenure in San Antonio to a conclusion.

According to ESPN's Adrian Wojnarowski, "few in [Popovich's] orbit" expect him to coach the Spurs beyond the 2020 Summer Olympics.

The five-time NBA champion will replace Mike Krzyzewski as head coach of Team USA in Tokyo and it looks like he may bow out of the NBA before it begins. 

But Woj stated that it's also possible Popovich will spend the 2019-20 season preparing for the Olympics, meaning 2018-19 could be his final season with the Spurs.

Big shoes to fill

Replacing Popovich will be a huge task for the Texas-based outfit as he's been at the helm since 1996. 

In that time, he's delivered five titles and named as Coach of the Year on three occasions. He has turned the team into a model of consistency as he's masterminded 21 consecutive winning seasons and the longest active playoff streak.

Pop is just one of five head coaches to win five titles with the same team - along with Phil Jackson, Red Auerbach, Pat Riley, and John Kundla.

He has a career regular-season record of 1,197-541, which puts him fifth all-time in wins. He will easily go down as one of the best coaches in NBA history. 

But he can't go on forever and it's clear that a glittering era will finish soon. The Spurs are coming off the back of a tough season where Popovich was challenged in many ways. 

Difficult year

They were in serious danger of missing out on the playoffs before eventually sneaking in by securing the number seven spot. 

San Antonio finished just 47-35 and this was the first time they'd won fewer than 50 games in a season since the lockout-shortened campaign of 1998-99.

There was also the saga with Kawhi Leonard as the superstar missed almost the entire year with a quad injury. 

As he's approaching his 70s, Pop may not have the stomach to continue with the grind of more 82-game seasons. 

On a personal note, Popovich's wife sadly passed away recently and the difficulty of this will also weight heavily on his decision. 

There's no doubt that when the day does eventually come and he retires, he will be celebrated for the legendary coach that he is. 

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