Sources: Gregg Popovich out indefinitely as Spurs turn to Mitch Johnson

San Antonio Spurs coach Gregg Popovich suffered a health issue before Saturday's game, and assistant Mitch Johnson is expected to be the interim head coach for an indefinite period of time, including Monday vs. the Clippers and Wednesday in  Houston, sources told ESPN.

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

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

"Mitch did a great job, man," Spurs guard Chris Paul said after Saturday's win. "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."

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