The San Antonio Spurs had to play Saturday's game against the Phoenix Suns without head coach Gregg Popovich for a very good reason. 

Per Tim Reynolds of the Associated Press, Popovich went to Springfield, Massachusetts, to attend Tim Duncan's induction into the Naismith Basketball Hall of Fame. 

Duncan told Reynolds that his bond with Popovich started when the Spurs coach flew to the Virgin Islands to meet with him before the 1997 NBA draft:

“It started there, it started with him going out of his way to want to know who I was as a person, wanting to meet my friends, wanting to meet my father, sit down and speak with him. It started there. And he built that trust from early on, just trying to understand who I was—not just as a basketball player, but as a person and beyond.”

Popovich was Duncan's head coach for his entire 19-year career. The duo won five NBA championships together and made the playoffs every year from 1998 to 2016.

The Spurs went 1,072-438 during that span and never won fewer than 50 contests in an 82-game season during Duncan's career. 

Three years after Duncan retired, Popovich brought him back to the Spurs as an assistant coach for the 2019-20 season. He made his debut as head coach on March 3, 2020, against the Charlotte Hornets when Popovich missed the game for personal reasons. 

Duncan stepped down as an assistant in November. 

Assistant Mitch Johnson served as the acting head coach for the Spurs on Saturday. They lost 140-103 to the Suns. 

San Antonio (33-38) has already clinched the No. 10 seed in the Western Conference and the final spot in the play-in tournament.