The 150-mile drive from Laredo to the AT&T Center went by in a flash for Mario Dominguez and his 9-year-old son, Mario-Andre, decked out in his LeBron James Miami Heat jersey and LeBron James signature Nike shoes. The elder Dominguez had paid $3,000 for two third-row seats for Sunday’s Spurs-Heat game so his son could see his favorite NBA player up close. The trip was easy. Learning that James, the three-time Most Valuable Player, was not going to play against the Spurs was more than hard. “He’s heartbroken,” the elder Dominguez said as his son buried his head in his father’s shoulder and tried to comprehend why he wasn’t going to see James in action. With the Heat having locked up the No. 1 seed in the Eastern Conference on Friday night in New Orleans, Miami coach Eric Spoelstra opted Sunday to sit James, All-Star guard Dwyane Wade and starting point guard Mario Chalmers, all with nagging injuries. James sat out the fourth quarter of the Heat’s easy victory in New Orleans with a tight right hamstring. He scored 36 points in the first three quarters of that game. The pain in James’ hamstring was nothing compared to what the 9-year-old Dominguez felt. “They get paid to do this,” his father said. “They’re famous and I understand being careful, but this is very hard.” James plays in front of fans wearing his replica jerseys in every arena in the league, and there were hundreds of those in the AT&T Center on Sunday. Van Robbins, a 24-year-old from San Antonio, was in his James jersey and wondered if Spoelstra’s decision was “revenge” for Spurs Coach Greg Popovich’s having sent Tim Duncan, Manu Ginobili, Tony Parker and Danny Green home to San Antonio rather than suit them up for a game against the Heat in Miami on Nov. 29. “I think the shoe is on the other foot,” he said, “but it’s sort of the same, too. The Spurs were the road team then and the Heat the road team tonight, so Spoelstra’s doing the same thing.