Despite winning the match 117-107 on home soil, the Spurs were given a major scare when Duncan was seen clutching his elbow after center Tiago Splitter fell on top of him with about a minute remaining in the game.
However, Popovich remains convinced that the 38-year-old will be back on the court in no time at all.
"I think he'll be OK, but what do I know?" Popovich told reporters after the game, in which Duncan scored 12 points, grabbed 13 rebounds, dished out two assists and blocked one shot in 36 minutes.
Meanwhile, Spurs point guard Tony Parker confirmed that Duncan's injury was not serious.
"They told us right away (Duncan's injury) was not big, so maybe half a second (of anxiety)," Parker said.