DETROIT — It’s a terrible stool sample.

The coaches in tonight’s national semifinal games will have an awkward adjustment to make during timeouts. Because of the raised court in Ford Field, the coaches — Jim Calhoun, Tom Izzo, Roy Williams and Jay Wright — will have to sit on small stools.

“I was hoping they would be nailed down,” Calhoun told The Post after his team’s practice. “I’m a big guy. I can see myself falling off.”

Sources told The Post that none of the coaches are thrilled with the setup. It forces the team managers and support staff to quickly arrange enough seating for the players and coaches, and then clear the court for play to resume.

“I guess if we get really upset we can throw ’em,” Calhoun said jokingly. “I wanted to practice it today but we didn’t get a chance. Watch, I’ll fall.”