This season has been tough for North Carolina.The Tar Heels are riding a four-game losing streak, calls for coach Mack Brown to retire have been present and loud, and the team has been grieving the passing of former wide receiver Tylee Craft, who died Oct. 12 after a battle with cancer.After a bye week, UNC has a chance to get back in the win column when it takes on Virginia in Charlottesville, Va., on Saturday afternoon.The last time the Tar Heels (3-4, 0-3 Atlantic Coast Conference) played was on the day Craft died. As Brown and others wore shirts emblazoned with Craft’s No. 13, UNC lost 41-34 to Georgia Tech after Jamal Haynes ran 68 yards for a touchdown with 16 seconds to play.To honor Craft, Brown said this week that the Tar Heels’ receivers will rotate who wears his No. 13 during practices and games throughout the rest of the season.”We’re going to keep his presence as much as we can without being awkward,” Brown said.The grieving Tar Heels have found a variety of ways to lose this season. They gave up 70 points at home to James Madison, blew a 20-point lead to Duke, turned the ball over on downs four times against Pitt, and then lost in the final moments to Georgia Tech.The common factor in those losses has been North Carolina’s defense, which is giving up an average of 399.9 yards per game — a mark that is tied for 101st in FBS.