Sources – Gregg Popovich is out indefinitely as Spurs turn to Mitch Johnson

San Antonio Spurs coach Gregg Popovich suffered from health issues before Saturday's game, and assistant Mitch Johnson is expected to serve as interim coach indefinitely, including Monday against the Clippers and Wednesday in Houston, sources told ESPN .

Popovich, 75, had a health scare before the Spurs' win over the Minnesota Timberwolves on Saturday night. The team said Popovich had an unknown illness.

The Spurs said Monday that Popovich did not travel with the team to games in Los Angeles and Houston.

“Mitch did a great job, man,” Spurs guard Chris Paul said after Saturday’s win. “I think our entire coaching staff [did]. Things are always happening in this league, and just like with players, it's the next man up. So, greetings to Mitch; He did a great job tonight.

Popovich is the NBA's career leader with 1,390 wins and another 170 postseason wins while winning five NBA titles. He is in his 29th season, all with San Antonio.