The 20-year-old power forward from Brampton, Ont., had surgery to repair a torn rotator cuff in his left shoulder, and is expected to miss both pre-draft workouts and the Summer League.
After his surgery, Bennett tweeted: "Everything is good, they said it went well , appreciate everyone that sent their wishes & prayers."
Later in the day, he tweeted a picture from the hospital, his left arm in a black sling.
Most mock drafts have the six-foot-eight Bennett going either fourth or fifth in the June 27 draft at the Barclays Center, home of the Brooklyn Nets.
Bennett played one season at UNLV, earning Mountain West freshman of the year honours. He started in 32 of 35 games, and led the team in scoring with 16.1 points a game. He also led the team, and was fifth in the conference, in rebounds averaging 8.1.
The Runnin' Rebels were upset in the second round of the 2013 March Madness tournament in a 64-61 loss to California.
Tristan Thompson is the highest Canadian NBA draft pick, going fourth overall to Cleveland in 2011.
Two other top-10 draft prospects for this year — Nerlens Noel and Alex Len — also had recent surgeries, Noel for a torn ACL and Len for an ankle injury.