Memphis Grizzlies forward Jaren Jackson Jr will be sidelined indefinitely with a right quadriceps injury, according to ESPN's Adrian Wojnarowski.
The Grizzlies will proceed cautiously with Jackson, who missed the Grizzlies' defeat against Los Angeles Clippers on Friday.
The 19-year-old had previously missed just one game as a professional in his rookie season - the loss against the Charlotte Hornets on February 1 with the same issue.
Jackon, who has made 56 starts from 58 games, is averaging 13.8 points, 4.7 rebounds, and 1.4 blocks in 26.1 minutes per game.
He produced 10 points and six rebounds for Team USA in the Rising Stars game on February 15 during All-Star Weekend.
As recently as last week, the Grizzlies announced they intended to make Jackson a bigger focus of their plans after the All-Star break.
"We've given him the rope to do more," coach J.B. Bickerstaff said, according to the Memphis Commercial Appeal.
"We expect him to take a step forward. We've asked him to do that."
Jackson was selected as the fourth overall pick in last year's draft.