Guard Andrew Wiggins has joined center Joel Embiid and forward Jabari Parker and decided not to participate in this week's NBA draft combine, sources told ESPN.com.
Duke's Parker and Kansas' Wiggins and Embiid are considered the top three prospects in this year's draft.
Kentucky forward Julius Randle and Australian guard Dante Exum -- both projected high lottery picks -- are expected to attend this year's combine, which will be held Thursday and Friday in Chicago.
Creighton coach Greg McDermott told ESPN.com's Andy Katz that his son Doug, a three-time All-American with the Bluejays, will do physical measurements in Chicago but wasn't sure he would do anything else.
Last year's No. 1 pick, Anthony Bennett, skipped the combine due to a shoulder injury.