The injury officially was diagnosed as a non-displaced fracture of the posterior talus in his right ankle. The Nets will announce a timetable for his return after the surgery.
"I was stunned, I was shocked. It's hurtful to be in that situation," said Hollis-Jefferson, who was in much better spirits while talking to reporters Monday. "Trying to be one of the best rookies, working really hard and then you get news like that, you don't really know what to say. You're at a loss for words."
Hollis-Jefferson injured his ankle in practice last week. It was initially called a sprain by the team.
"I was guarding [Bojan Bogdanovic]," Hollis-Jefferson said. "I mean, it just happened. It was a really bad roll."
Hollis-Jefferson, a promising defender, is averaging 5.2 points, 6.1 rebounds and 1.4 steals per game. The 20-year-old has made 14 starts this season.
"We're going to miss his physicality, his size, 6-7, his ability to go get rebounds, get hands on the ball," Nets coach Lionel Hollins said. "We're going to miss that. But how much, how bad? We'll have to see as we go along.
Bogdanovic will be tasked with starting in place of Hollis-Jefferson. Bogdanovic is averaging just 4.3 points on 32.1 percent shooting in his past 11 games.