Egbunu, a redshirt junior from Nigeria, suffered the injury during the first half of Florida's 114-95 victory against Auburn on Tuesday. He was averaging 7.8 points and 6.6 rebounds for the No. 15 Gators.
"We're all disappointed for John," coach Mike White said in a statement. "He's been playing really well of late, so it's a tough blow to him and our team. He's a great young man, and unfortunately injuries are a part of basketball. He'll be back even stronger."
Egbunu started his career at South Florida before transferring to Florida after his freshman season. Egbunu averaged 11.5 points and 6.5 rebounds last season for the Gators.
With Egbunu out, White will look to senior Justin Leon and sophomore Kevarrius Hayes for more production down low. Leon is averaging 12.7 points and 6.7 rebounds in his past three games, while Hayes had nine points against Auburn.
Freshman center Gorjok Gak, who hasn't played in the past four games, suffered a sprained foot in practice Monday and will miss up to two weeks.