BERKELEY — Robert Thurman always figured he'd be big. His mom is a retired Marine staff sergeant who stands 6 feet tall, while his father is a 7-foot former bodybuilder who weighed 400 pounds in his prime.

Thurman's frame is largely what landed him a roster spot for Pac-12 contender California.

In a matter of weeks, the 6-foot-10 Thurman has moved from way down on the bench to being right in the mix for the Golden Bears.

The former walk-on arrived at Cal three years ago fully expecting to wind up as a practice player, a fun side gig while getting a top-notch education.

He sat out his first year after transferring from Division III Norwich University in Vermont, then tried out last season. At his height and considering Cal's thin frontcourt, coach Mike Montgomery had every reason to give Thurman a chance.

He's now known as the "Thurmanator," will dunk when given the chance and gives the Bears a big body off the bench.

"It's weird because I've never been in this type of position before. It's kind of cool. I like it," Thurman said. "I'd rather have that role than just the role of not doing anything."

Suddenly, Thurman is a reliable player in the low post and on scholarship for a Golden Bears team (17-5, 7-2) competing for the inaugural Pac-12 title. Montgomery counts on key minutes from Thurman after the departure last season of 7-foot-3 Chinese center Max Zhang, who went back to his home country, then the recent loss of Richard Solomon when he became academically ineligible. Omondi Amoke was dismissed by Montgomery in April 2010 for violating team rules.

While Thurman might have caught some teams off guard early, opponents surely will start taking notice.

"That's going to definitely change," Thurman said. "That's the reason why I would say I've had some of the open looks I've had because they're like, 'This kid's some walk-on, just leave him open.' I'm sure I'm already on some people's scouting reports, 'Don't leave open for a wide-open dunk.'"

Montgomery received a letter about Thurman and knew little more than he was 6-10. Cal did minimal research — "not much," Montgomery admits — but decided to give Thurman a hard look.

"We didn't have a lot of bigs," Montgomery said.

It took only a quick glance to know that Thurman was not only big but athletic and well-rounded. He averaged 16.7 points, 12 rebounds and 3.5 blocks during his high school career, was on the honor roll all four years and also took part in football, volleyball and cross country.

"Being a military kid, he was exposed to a lot of different cultures, exposed to a lot of different things," his mother, Shelley, said. "That helped. I've always taught him that when given an opportunity he needs to make the best of his opportunity."

Thurman realizes his timing has been fortuitous.

He appeared in all of 10 games last season as a sophomore — 28 minutes total — and took two shots while grabbing nine rebounds.

"Honestly I thought my role was just going to be a practice player and be a college student ... and every once in a while at the end of the game get mine when I can, but that changed," Thurman said. "Things just started to happen for me. My role changed this year compared to my role last year, and it probably would have been different if those guys hadn't left. Just a strange turn of events throughout my career here."

On Jan. 19, Thurman came off the bench to score a career-high 16 points in 21 minutes of an important 69-66 road win at Washington.

"(Robert) is a big guy and he gets his hands on some balls," Montgomery said after Sunday's 69-59 win over rival Stanford. "He's getting an opportunity."

Born at Camp Pendleton near San Diego, Thurman learned from a young age how to adjust in any given situation. He moved eight or nine times growing up — he lost track — as a military brat and became accustomed to the difficulties of saying goodbye to close friends along the way. His mom often faced long deployments, so Thurman and his younger sister spent much of their time with dad.

"We always had that one, solid parent around," Shelley Thurman said. "When we moved, we tried to make that transition as smooth as possible. They'd help us pack, they'd help us tour the community."

These days, Shelley Thurman has slightly more flexibility in her schedule and can see her son play. Retired from the Marine Corps in 2008, she lives outside Edwards Air Force Base in Southern California and currently works at the same desk she did while in the military — serving as a government contractor supervising civilian helicopter mechanics.

Thurman respected his mother's input and insistence that he pursue his goals, never daring not to listen to her because his father "was just so big and scary."

"She would definitely get on my case," Thurman recalled.

He appreciates her for giving him that extra push along the way.

Cal toured Scandinavia for 10 days in August, and Thurman began to thrive.

"The Scandinavian trip really put my role in perspective here at Cal," Thurman said. "I kind of realized I needed to be more of a player on our team. We needed to have someone who could score and rebound. That wasn't my first role. My first role was to rebound, defend and screen, and I'm doing that. The scoring is just a bonus — I guess teams not really thinking I'm a threat when I'm right next to the basket, and I can just dunk it."

Thurman's presence and persistence have helped take some pressure off Cal's stars, like last season's conference freshman of the year, Allen Crabbe.

"He's done a great job so far. When Robert comes in, he can score and he's a big body," Crabbe said. "People didn't see him as a threat. They'd probably never heard of him. Now, when you see a kid come off the bench and score 16 points, I'm sure that's going to open up the other team's eyes."