TEMPE, Ariz. — Keegan Herring’s million-watt smile lit up Arizona State’s football offices when he arrived in 2005, promising to become the next great Sun Devils tailback.

The toothy grin remains, but it had a different meaning this year. It was a defiant response to an unfathomable series of family tragedies.

Herring tried to smile through the deaths of his father, sister, best friend and aunt, all in the span of four months.

And he kept on smiling when he lost a battle for the starting tailback job in training camp.

How he did it is anyone’s guess.

“There’s been a lot on me, but the type of person I am, I always like to see other people smile,” Herring said. “It was a hard thing to do, but if I keep people smiling, they’ll keep me smiling. And that will bring a lot away from the pain I’ve been suffering through this year.”

Herring, who hurt his ankle in the regular-season finale against Arizona, is hoping to return when the 12th-ranked Sun Devils meet No. 17 Texas in the Holiday Bowl on Thursday night.

For many here, the 20-year-old Herring has become a beacon of uncommon strength and resilience.

“I tell him that with everything he’s gone through, he’s a role model,” said Corinne Corte, Herring’s academic advisor. “There’s just a light that shines from him.”

The Holiday Bowl will cap 10-2 Arizona State’s best season since 1996. It will also mark the end of a harrowing year for Herring, a junior from Peoria, west of Phoenix.

Tragedy first struck last Feb. 11, when Herring’s best friend, Calvin “C.J.” Adams was shot to death at 19. As boys, they had played on the same Pop Warner football team.

“The one thing, when I close my eyes and imagine him, it’s the funny smile he had,” Herring said in an interview last week. “Big belly, I used to call him. I used to slap him in the stomach.”

Three days later, Herring’s father Freeman also was shot to death, at 47. Herring rushed home to be with his mother, Debra Griffen.

“Right when that incident happened, I mean, I think that’s where me and my mom automatically connected — mind, soul and everything, you know?” Herring said. “We just connected. I’m showing so much love for her now, because you never know. You think during the day that you want to be mad at your mom, but at the same time, you know anything can happen, so you hurry up and call her or text her with ‘I love you.’ ”

After burying his dad and best friend, Herring threw himself into spring drills and offseason conditioning. In 2005, Herring had rushed for 870 yards, most ever by an ASU freshman, but he had taken a step back a year later. Now Herring was ready to challenge for the starting job under ASU’s new coach, Dennis Erickson.

Then came June 17, a blistering day in the desert. Herring’s sister, Denisha Washington, was killed in a car accident. Three days later, an aunt died of a heart attack at her desk.

Herring spoke at his sister’s funeral, offering mourners a message of hope.

“He told all of us to turn to the person to the right and turn to the person to the left and tell them we love them,” Corte said. “Because you never know it will be the last chance you’ll have to say that.”

After yet another double blow, Herring’s friends and advisors urged him to take some time off, let the wounds heal.

“My impression of what he went through is that it was just overwhelming,” Corte said. “I said, ‘This is more than people can handle and deal with.’ ”

Teammate Rudy Burgess, one of Herring’s closest friends, was concerned that Herring was taking on too much.

“I even suggested to him, don’t worry about football,” Burgess said. “Take a break. Football isn’t that important right now.”

But Herring decided he needed football more than ever.

He was numb to the ritual of funerals and burials. He sought the ritual of pulling on pads and stepping onto a blazing practice field, where he would absorb a different kind of pain — the kind he was conditioned to handle.

“It just felt like the whole world was going to come down on me at once,” Herring said. “Can I take it, can I not take it? That was the most I’ve been tested in life. Nothing could get worse than that. It probably can, but that was just too quick.”

Corte kept a close eye on Herring, who seemed withdrawn at times. But even on the hardest days, Herring managed to smile — and make others do the same.

He made a game of it, telling strangers that he was collecting smiles, and would they mind giving him one? Even a little one?

People who didn’t know Herring’s story might wonder about this goofy kid. But they’d almost always be chuckling as he walked away.

Herring’s next test came in August at Camp Tontozona, where he dueled Ryan Torain for the starting tailback job. Torain, a senior, prevailed.

Herring finished with a team-high 816 rushing yards and five touchdowns.

As Herring’s story has been told, he earned nominations for a couple of national awards recognizing courage.