The Springfield College crowd gasped in disbelief, then roared its approval. 

Everyone had come to see a rare high school matchup of studs, between Doc Rivers’ son Austin Rivers and Duke-bound Tyler Thornton, but it didn’t take long for Rivers to steal the show…

That tends to happen when a player follows up a vicious first-quarter dunk in a helpless defender’s face with a gravity-defying alley-oop on the very next possession.

The crowd knew Doc’s child was going to be good — he is rated #2 in the junior class — but few realized how electric he would be.  He made his presence known with those dunks, but Austin Rivers’ game was far more complete than merely his aerial arsenal could reveal.

After those two dunks let the crowd know they were witnessing someone special, Rivers displayed a crispy, quick crossover and a devastating first step.  He showed a series of polished jab step moves that left his defenders grasping for air, and a handle most point guards would be jealous of.  He carried himself like a star, with a cocky gait that belied his otherwise humble demeanor.

His matchup with Thornton was touted as a competitive meeting between two highly-ranked recruits, but Rivers left no doubt he was a far superior player.  The day at Springfield’s HoopHall Invitational, one of the top high school tournaments in the country, featured the top senior recruit in the country and players committed to UNC, Ohio St., Duke among plenty of other Division 1 schools, but Rivers was still the unrivaled cream of the crop.

His father, watching from a secluded second-floor overpass, must have been a proud man.  On a day featuring plenty of high school stars in their own right, Doc’s son shone the brightest.  He commanded the crowd’s respect and admiration with his first-half flurry of dunks, then drilled off-the-dribble three-pointers on three consecutive second-half possessions to give his team its first real cushion of the game.

Then, as suddenly as Austin Rivers’ dunk made the crowd stand to its feet, he caused it to deflate when he fell to the ground in apparent agony after trying to split a double team.  As Rivers sat writhing on the floor, his mother raced out of her second-floor perch next to Doc, running down the stairs to her son’s aid as the silent crowd watched Rivers roll around in discomfort and listened to his shouts of pain.

A few seconds later, after Rivers was carried off the floor and brought to the trainer’s table, holding his face to hide the emotions his injury had left him,  Doc Rivers joined his wife and son.  As Doc walked down the stairs to provide his son support, the crowd erupted once more in a cheer.  Just like his son had earned the crowd’s admiration and respect with his play, Doc has with his coaching.  As the certainly-worried parent trailed after his injured son, he gave a wave of his hand to acknowledge the crowd and thank it for its support.

At the time, watching Austin’s reaction and not able to determine whether it was a knee or ankle injury, I felt his injury could possibly be very serious.  I worried he might never again reach the potential he’d shown so many glimpses of in the one game I saw him play.

The injury turned out to be only an ankle sprain, but watching Rivers squirm on the floor illustrated what the Celtics have already learned this season and last.

Greatness and health, especially in sports, can be very fickle things.