Johnson was informed about 2½ hours before Saturday’s tipoff against the Minnesota Timberwolves that the 75-year-old Popovich was unavailable due to an undisclosed illness.

“He’s not feeling well,” Johnson said. “This has happened before. I think everyone always needs to be prepared for the next guy. We deal with injuries and sometimes people get sick or don’t feel well or things happen in life. He’s just not feeling well.”

It was the third time Johnson served as head coach in Popovich’s absence. Former assistant coaches Tim Duncan and Becky Hammon also served as Spurs head coaches for the past five seasons due to Popovich’s illness or medical procedure.

San Antonio defeated Minnesota 113-103 on Saturday.

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.