San Antonio Spurs head coach Gregg Popovich will reportedly be sidelined indefinitely after he missed Saturday’s game against the Minnesota Timberwolves with an undisclosed illness.

Spurs assistant coach Mitch Johnson took over for Popovich on the bench. He said at the time he was informed about two and a half hours before tipoff that the legendary coach was going to miss the game.

CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COM

"He's not feeling well," Johnson said Saturday night. "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."

ESPN reported Monday that Popovich will be sidelined for a while. The team told the outlet that Popovich did not travel with the team for road games against the Los Angeles Clippers and Houston Rockets.

Popovich, 75, is the NBA’s career leader in wins with 1,390 victories. He is in his 29th season with the Spurs and has five NBA championships on his resume.

BUCKS' BOBBY PORTIS REVEALS HOME WAS BURGLARIZED DURING GAME VS CAVALIERS

The Spurs won the game Saturday with Johnson guiding the team.

Keldon Johnson scored 25 points, and Chris Paul had 15 points and 13 assists.

"Mitch did a great job, man," Paul said, via ESPN. "I think our whole coaching staff [did]. Things happen within this league all the time and just like with the players, it's next man. So, shoutout to Mitch; he did a great job tonight."

The Spurs are 3-3 to start the year.

The Associated Press contributed to this report.

Follow Fox News Digital’s sports coverage on X, and subscribe to the Fox News Sports Huddle newsletter.