Adrian Wojnarowski of ESPN wrote on June 1 that Morant was scheduled to have a "minor arthroscopic procedure" on his right knee on June 3. Recovery time was expected to be three to four weeks.
Morant confirmed on Twitter that the surgery was successful.
Summer-league action in Las Vegas, where all 30 teams will be represented, is slated to begin July 5.
Morant told reporters on Wednesday his knee didn't hurt and that he expected to play in Las Vegas, but plans have since changed.
Although Morant should be 100 percent by July 5 given Wojnarowski's estimated recovery timeline, there's no need for the Grizzlies to risk further injury for their new franchise player.
Morant should immediately start at point guard for Memphis, who traded 12-year veteran Mike Conley to the Utah Jazz. With the season beginning in October, Morant has plenty of time to get well before he takes the floor for meaningful games.
The former Murray State star posted 24.5 points on 49.9 percent shooting, 10.0 assists and 5.7 rebounds for the Racers during his sophomore season. He joins a rebuilding Grizzlies team whose future is based around an exciting core of Morant and Jaren Jackson Jr., who averaged 13.8 points on 50.6 percent shooting last season after being drafted fourth overall in 2018.