Greg Filer III didn’t care that people told him it was a mistake to bet on himself. Coming out of high school, he had a partial offer from Division II Western New Mexico, and the confident Filer was certain he could do better.

“Who are you to say what I'm going to do?” Filer would reply to his doubters. “You don't see the future.”

Filer had his sights set on Division I. His older brother John Ross played at Washington and now is with the Cincinnati Bengals.

He wondered: If his brother could do it, why couldn’t he?

The winding path Filer took to Montana State went through four high schools and two junior colleges. Compton College won two games in the two seasons he was there. None of that mattered. Filer’s persistence never wavered. When he finally received an offer to MSU, he committed before he even visited. His chance finally came, and he wasn’t going to hesitate before he took it.

“I knew if I worked hard, kept my head down and just worked my hardest, I would get to where I want to be one day,” Filer said. “That's exactly what I did, and I'm here today.”

Entering today’s season opener against Western Illinois at 7 p.m. at Bobcat Stadium, Filer is listed as MSU’s backup boundary cornerback. The junior’s role could increase as he grows more comfortable with the Bobcats and adjusting to new situations is anything but new for Filer.

Growing up in Compton, California, Filer didn’t mind attending four high schools. Each move was calculated and mostly related to each school’s coaching staff or football team. At no point did he stray far away from where he was raised.

After graduating from Paramount High School in 2015, Filer didn’t play the following season and thus saved a year of eligibility. He struggled receiving financial aid so he dropped all his classes at Long Beach Community College and “was kind of like living real life.” For the first time in more than 10 years, Filer experienced a fall without playing.

Football shielded Filer from outside dangers in Compton. He viewed the sport as his escape.

“When you come from a certain place, you're immune to everything that's going on. So it's kind of regular. It's kind of like second nature to me,” Filer said. “There's a lot of negative things that go on around there of course. Everyone knows that. But I never put myself in position to be in those types of situations.”

Filer then spent the next two seasons at Compton College working with his cousin and defensive backs coach Reco Robinson. Every day, the two practiced something different, from playing press and zone coverage to improving speed and studying film.

The 6-foot, 170-pound Filer possesses long arms and explosiveness. Robinson told Filer once he learned the nuances of cornerback, a position he never fully committed to until college, he could thrive in Division I.

A turning point came in the final game of Filer’s freshman season. Compton held a two-point lead in the closing seconds, but its opponent was driving. An errant throw flew over a receiver and into Filer’s hands. Filer came “out of nowhere,” Robinson said, returned it for a touchdown and pandemonium ensued as Compton won its only game of the year.

"I saw his confidence go up, and mentally he started knowing, 'I could really do this,’” Robinson said. “‘I could really get somewhere from here.'"

Robinson reminded Filer the scoreboard wouldn’t be shown in his highlight tape. Filer wouldn’t let his team’s struggles drag him down.

He ignored those who told him he could play at a higher level and instead channeled his focus toward creating that reality. Filer said his belief in himself makes him stand out.

“He has a never-die attitude,” Robinson said. “If he's going down, he's going to go down in flames.”

The biggest difference between MSU and the schools he’s previously been at, Filer said, is how far from home he is. Every time an issue comes up, he calls his brother who’s two years older than him.

The two grew up together with their single mother, and Ross filled the role of a father figure in Filer’s life. If it wasn’t for his family, Filer said he wouldn’t be with the Bobcats. Regardless of the situation, they supported his aspirations. He buckled down academically, improved athletically and accomplished what he set out to do.

“He understands he's here for two reasons, that's school and ball,” MSU secondary coach Mark Orphey said.

When Filer arrived on campus, he expected a more challenging adjustment. Even though he was playing at a higher level and away from where he grew up, he wasn’t overwhelmed by the football aspect of the change.

During fall camp, entire days are scheduled out for the Bobcats. What time they wake up, eat, lift weights, hold position meetings and even shower is planned, head coach Jeff Choate said. Filer heard from Ross that this is what it’d be like, but he wanted to experience it on his own.

“Bozeman's a very different place than Compton, California. ... Learning a routine and how we do things and how we operate can be a challenge, but I think he's really embraced it,” Choate said. “I think he's really fit in well with his teammates. He's been very coachable. I think he's just excited for the opportunity, and he's looking forward to a chance to play Division I football.”

As the season kicks off, Filer is still learning the intricacies of the scheme. Defensive coordinator Ty Gregorak recently asked him if he knew what a rhetorical question was because he frequently answers when they’re asked in team meetings.

But then again, Filer didn’t get to where he’s at by sitting idly by.

“I'm just trying to make the best out of my opportunity ... There's not really too much to it,” Filer said. “Just getting out of the hood, just trying to make a way.”

Paul Schwedelson can be reached at pschwedelson@dailychronicle.com or 406-582-2670. Follow him on Twitter @pschweds.