Maybe the signs were there all along last season that Mike Krzyzewski was ready for an exit: scolding a student journalist for an innocuous question, having an N.B.A. prospect quit midseason to prepare for the draft, and openly questioning whether there should be a season while the coronavirus was rampant in the United States.
And, of course, Duke being absent from the N.C.A.A. men’s basketball tournament for the first time in 26 years — a circumstance set up by a 13-11 start and cemented by a late-season virus outbreak within the program.