Billy Garrett Jr., by all guesses the nation’s only college basketball player with sickle cell disease, can recount in detail each painful crisis triggered by his condition. There was the dehydration during a summer camp in a broiling gym that left him in need of a blood transfusion. There was a less serious episode during his freshman year at Morgan Park High School, after his mother’s birthday and before a game against powerhouse Simeon High, prompted by overexertion. And in January, there was the telltale ache in one knee after a DePaul practice that became stabbing pain in both legs just as a road trip began. It led to vomiting from over-medication, the loss of 10 pounds and an extended stay in New Jersey as Garrett Jr. recovered for days in a Newark hospital. He missed two games and then had to rebuild the strength in his legs. It was the cost of pursuing a passion that tests his disease daily, with a near-constant risk of dehydration and exhaustion and stress that can trigger terrible pain. The freshman point guard and former top 100 prospect bears the load of leading the Blue Demons program, but that burden barely compares to opening himself to crises few can conceive. “Doctors have told me basketball probably isn’t the best thing for me to do, that I should try other things that aren’t as strenuous,” Garrett Jr. said. “But I’ve been able to handle it. It’s worked out for me. I’ve been playing for so long I never really thought about not playing basketball. I’ve never really thought about, ‘I can’t do this because of the sickle cell.’ It hasn’t been easy, but I really didn’t want anybody to tell me I couldn’t do it.” He has been mostly right. The Blue Demons (11-8, 3-14 in the Big East) close their season Thursday, but Garrett Jr. exceeded even his coach’s expectations by averaging 12.4 points and 3.2 assists. He has stated a case for Big East Rookie of the Year despite his disease and the games he has missed because of it.