He looks different now. But then, that’s what selfless acts of bravery can do to a person.

Greg Ostertag will tell you that he’s the same as before. And in so many ways, he is. He still wears a whimsical smile wherever he goes. That goofy Fred Flintstone tattoo remains on his right calf, and the Utah Jazz center still sports a crew cut that makes him look as if he just enlisted in the military.

In his words: “I’m just living. Playing ball and having fun, ya know? That’s all it is. So don’t go try to make too much out of anything.”

This comes from someone who risked his basketball career and the millions of dollars he makes from the NBA.

“To be honest,” he said, “I didn’t think much about it.”

That’s how things work inside Ostertag’s head. He never seems to give anything too much thought. That’s the good and bad trait of his character.

That’s what drives coach Jerry Sloan crazy and teammate Karl Malone into a fighting frenzy. If only the 7-foot-2, 280-pound Ostertag cared about the pursuit of a championship as much as they did. Then, maybe the Utah Jazz would have made good on one of those two NBA Finals appearances.

But their happy-go-lucky center from Duncanville, Texas, has always lived by a different motto than his NBA brethren. He has always said that he’s a work in progress and has yet to live up to the potential of someone selected in the first round (28th overall) of the 1995 draft out of Kansas University.

“Someday, I’ll grow up,” he promised. “I’ll get it.”

And perhaps Ostertag has matured more than he realizes. Maybe his basketball priorities aren’t in sync with those around him, but he seems to have a grasp on the stuff that really matters.

So when his sister called and needed help, Ostertag never gave it a second thought.

“Of course,” he said.

But this request was different. She didn’t need to borrow his car or help with the rent. His sister, Amy Hall, needed a kidney, and Ostertag was a perfect match. He had known for the past two decades that she was sick. Hall, 27, has battled Type 1 diabetes since she was 7. In his mind, Ostertag believed he’d always do the right thing should the need arise.

But here he was, 29 years old and months from beginning an eighth season as a starting center. The Jazz were going to pay him $7.8 million this season, and $8.7 million the next, but all of that was in jeopardy if he said yes.

There was no precedent for this type of gift. No NBA player had donated a major organ during his playing career.

Nearly seven months later, life has returned to normal.

Hall returned to her job in the accounting department of a Dallas law firm, and Ostertag resumed his NBA life. Every so often, he is asked about his act of charity, to which he shrugs off the gesture in an “aw-shucks” kind of way.

Some things, I imagine, are better left unsaid, just as many accounts of generosity tend to go unnoticed.

But Ostertag gets recognized now more than ever. At home and in opposing arenas, fans will stop him and congratulate him. When this happens, he gets embarrassed.

“I didn’t do this to change my reputation,” he said.

But that’s exactly what Ostertag did.