Jefferson made the announcement through the school Wednesday. He has the option to return to school for his final season of eligibility after going through the evaluation process by league executives.
He started 29 games in his junior season and averaged 9.4 points and 5.5 rebounds. He shot 59.9 percent from the floor in Big East games to rank fourth in the conference.
Players have until June 3 to withdrawal from the draft and retain their eligibility as long as they haven't signed with an agent who is not certified by the NCAA. The draft is scheduled for June 25.