The news of Whittington's injury was reported by ESPN.com on Monday night, and the severity was confirmed by a Georgetown spokesman on Tuesday afternoon. The 6-foot-8 sophomore forward suffered the injury a little more than a week ago.
"Greg will return when he is 100 percent healthy," Georgetown coach John Thompson III said in a statement. "I feel for Greg because he's worked extremely hard to prepare for the coming season, on and off the court. I'm confident this is just another setback that in the end will make him even stronger. At this point, there is no specific timetable for his return."
Whittington averaged 12.1 points and seven rebounds last season before being ruled academically ineligible prior to the St. John's game on Jan. 12. He played 13 games this past season and was expected to help ease the loss of Big East Player of the Year Otto Porter -- who left early for the NBA.
Thompson told CSNWashington last month that Whittington would return to the team after missing the final 19 games of the season.
The Hoyas finished 25-7 last season and lost to Florida Gulf Coast in the round of 64. Thompson returns starters Markel Starks, Nate Lubick and D'Vaunte Smith-Rivera and will also add UCLA transfer Josh Smith after the first semester.
Georgetown will open the season against Oregon in the Armed Forces Classic on Nov. 8 on ESPN at an Army base to be announced soon. The Hoyas will play in the new Big East with six other old Big East schools as well as newcomers Butler, Creighton and Xavier in the 10-team league that will debut next season.
Jeff Goodman covers college basketball for ESPN.com.