Gregg Popovich, the 75-year-old coach of the San Antonio Spurs who sat out his team’s win Saturday night due to an undisclosed health condition, now is not joining the team on its two-game road trip to Los Angeles and Houston, the team announced.

Assistant coach Mitch Johnson has moved into the head coach’s seat in the interim (which could potentially be longer than just these upcoming two games). Johnson played down the seriousness of the situation before the Minnesota game, via Tom Osborn at the Express-News.

“He’s not feeling well. This has happened before. I think everybody’s just always got to be ready for the next man up. We’ve had it with injuries and sometimes people get sick or don’t feel well or things come up in life. He’s just not feeling well.”

Under Johnson, the Spurs beat the Timberwolves to improve to 3-3 on the young season.

Popovich is a coaching legend and Hall of Famer. He has helmed the Spurs for 29 years, is a five-time NBA champion and coach of the USA’s gold medal team at the Tokyo Olympics, and is the NBA’s career leader in coaching wins with 1,390 (plus another 170 in the playoffs). His coaching tree casts a massive shadow across the NBA, including Steve Kerr (Warriors), Mike Budenholzer (Suns), Ime Udoka (Rockets), Taylor Jenkins (Grizzlies), Mike Brown (Suns), and many others have learned from the master.