Ryan Thorburn / The (Eugene) Register-Guard

Mark Helfrich received a call from Chip Kelly five years ago that dramatically changed his career path.

The first-year Oregon head football coach may have done the same for Cha’pelle Brown by hiring the former Colorado player to be a defensive graduate assistant coach with the Ducks this season.

“I guess I did things right at Colorado to be fortunate enough to be on this coaching staff,” Brown said after Monday’s practice as Oregon began preparing for its road trip to Boulder this weekend to face the Buffaloes. “I always knew I wanted to be a coach after football. It’s something that I’ve been working towards even as a player. It’s always something I knew I wanted to do.”

When Helfrich was the offensive coordinator at CU from 2006 to 2008, Brown was a standout cornerback. The connection has paid off so far for the Ducks’ new head coach and the baby-faced member of the veteran Oregon staff.

“He was always just someone that I thought was a really intelligent guy, a really positive guy and someone I thought our guys would benefit from being around,” Helfrich said. “I think he’s a guy that has a very bright future if he chooses this profession.”

Brown played in 46 games for CU during his career. As a senior in 2009, the diminutive defensive back was voted most valuable player by his teammates and All-Big 12 second team by the coaches he competed against.

As a budding coach, Brown, 25, has not only great rapport with his players but an understanding of how they think.

“I told them, ‘I’m almost as young as you, so you can’t trick me,’ ” he said with a laugh. “It’s great to be able to work with them.”

When Helfrich was hired at CU, he was the youngest offensive coordinator at a BCS program. Brown’s youth has also served him well this season working with Oregon’s accomplished defensive secondary.

“He’s a players’ coach,” Ducks cornerback Terrance Mitchell said. “He played the game and knows what it’s like.”

The Ducks currently rank ninth nationally in passing efficiency defense, allowing only 186 yards per game with four interceptions.

During the 55-16 victory over California, the combination of Nick Aliotti’s relentless defense and a severe rainstorm led to freshman quarterback Jared Goff, the nation’s leading passer entering the game, getting benched early.

Oregon’s three top cornerbacks — Mitchell, Ifo Ekpre-Olomu and Dior Mathis — each has one interception through four games.

“When he becomes a head defensive backs coach, he’s going to be great,” Mathis said of Brown. “He does great work with us already. That’s one of my favorite coaches already. I love him. Taking his advice has helped a lot. Not just me, but everybody in the defensive backs unit. It’s a pleasure having him. ...

“We can relate to him a lot. He’s not too much older than us and he has been through a lot, just as we have been through a lot.”

The Ducks have not suffered through nearly as many losses as Brown did. CU was 16-33 during his playing days.

During the 2008 season, Brown returned an interception for a touch down in the final two minutes to provide the Buffs with a 31-24 victory over Eastern Washington. After the dramatic escape, CU safety Ryan Walters said: “He’s so short, probably the quarterback didn’t see him.”

Helfrich certainly took notice of the 5-foot-7 Brown during practices.

“He was a guy that obviously didn’t fit the mold of a stereotypical player with size and speed and height,” Helfrich said. “He overcame it with great leadership and he was a technical guy and he was a vocal guy.”

Right now, Brown is listening closely to everything longtime Oregon defensive backs coach John Neal, who has 31 years of experience, says. Brown was also mentored at CU by Greg Brown, a well-respected secondary coach now working under Nick Saban at Alabama.

“Coach Neal is one of the best coaches in college football, so to be able to learn from him and work with these players has been great,” Brown said. “As a player, coaches are the people in your life that you spend the most time with as you go through those phases from a young man to a man. (Greg Brown) was a huge part in me wanting to be a coach.”

Being on the visiting sideline this Saturday when No. 2 Oregon plays CU at Folsom Field is something Brown is looking forward to.

“When I get there, it will be a good thing to see some old friends,” Brown said.

“But right now I’m a Duck.”

Oregon’s Thomas likely to sit out against Colorado on Saturday

EUGENE — Oregon running back De’Anthony Thomas is unlikely to play against Colorado this weekend after emerging from practice wearing a boot on his injured right ankle.

Running backs coach Gary Campbell told reporters on Tuesday that the speedy junior’s return is “not going to happen” when the No. 2 Ducks (4-0, 1-0 Pac-12) visit Colorado (2-1, 0-0) on Saturday.

Thomas was injured on the opening kickoff of second-ranked Oregon’s 55-16 victory over California on Saturday night, slipping on turf that was slick from a driving rain.

— The Associated Press