As a senior at Edgerton (Wis.) High School, 49ers tight end Derek Carrier came to a fork in the road.

Carrier’s choice: Accept an offer to play at Division I blueblood Wisconsin as a preferred walk-on, or attend Beloit (Wis.) College, a brainy Division III school that had never produced an NFL player?

His decision: The path likely to take him light years away from the NFL.

Former Beloit head coach Chris Brann says Carrier’s choice to eschew the Big Ten for the Midwest Conference was a stunner. But Carrier, a pre-med major who graduated summa cum laude, wanted to attend a top-notch academic school where he could play multiple sports. He also played basketball for two seasons and ran track one year at the private liberal-arts college of 1,300 students.

“In 22 years of coaching college football, I’ve had very few players that were preferred walk-ons at a major Division I school that came to us,” Brann said. “What led to that? Derek’s priorities were in order and he made the decision based on what was on his heart at the time.”

Said Carrier: “Wisconsin told me I would get redshirted for sure and probably not play until my junior and senior year. That sounds like a great deal to a lot of kids, but I wasn’t thinking about playing in the NFL at that point in my life.”

So Carrier’s heart took him to Beloit, where, improbably, his legs still led him to the NFL.

A wide receiver in college, Carrier was a four-year starter who set school records for receptions (189), yards (3,111) and touchdowns (29). NFL scouts yawned at his numbers against the future stockbrokers of Lake Forest and Lawrence, but Carrier’s 2012 pro-day performance before representatives from all 32 teams at Wisconsin demanded their attention.

At 6-foot-4 and 238 pounds, Carrier ran a 4.51-second 40-yard dash, had a 40-inch vertical jump and ran the three-cone drill in 6.69 seconds. For perspective, his vertical jump would have ranked fourth and his three-cone time would have been second among wide receivers at the 2012 NFL combine.

His agent, Ron Slavin, from Madison, Wis., no longer had to promote his once-anonymous client after Carrier’s performance.

“It was really off the charts, so that’s when the interest started,” Slavin said. “Scouts started seriously watching his film and realizing what an athlete he is. I talked to all 32 teams about him.”

Just over two years later, Carrier, 24, is the only Division III product on the 49ers’ 90-man training-camp roster. But the former undrafted free agent isn’t an overnight small-school success story.

After spending 2012 on the Eagles’ practice squad, Carrier was signed to the 49ers’ practice squad last year and made his NFL debut in November when tight end Garrett Celek was sidelined by hamstring injury. Carrier played 45 snaps in five games, was inactive in five others and didn’t have a reception.

This season, he’s battling Celek for a roster spot as the No. 3 tight end. Celek hasn’t participated in the first seven training-camp practices because of a back injury, which has given Carrier an opening to cement a job.

To do so, Carrier needs to continue to progress as a blocker, a must-have ability for tight ends in an offense that’s ranked among the NFL’s top seven in rushing attempts the past three seasons.

“If you’re going to play in the core of the formation you’ve got to be a winning player in the run game in some way,” 49ers offensive coordinator Greg Roman said. “And Derek has the raw tools to do it, but he’s got to do it consistently.

“He’s got a chance to be a productive player in this league. There’s no doubt. Derek’s got a nice feel for the passing game, he’s got good hands and he can cover some ground now — he can really run. I don’t like to put timetables on people, but this a big year for him. He’s got a hell of an opportunity this year to really take a big step.”

Carrier never imagined he’d have an opportunity to play in the NFL until midway through his college career when, Brann says, “opponents were scared of him and didn’t want to tackle him.” Carrier stopped playing basketball after his sophomore season and devoted himself to one sport.

“I decided to stick with football and see where that would lead me,” Carrier said. “You ask anyone out here – the opportunity to plat ay this level is once in a lifetime. If you even have the chance to play at this level, you have to take advantage of it.”

If Carrier’s career doesn’t develop, his education has provided him with an attractive fall-back option. After sporting a 3.95 GPA in high school, and making the dean’s list for six straight semesters at Beloit, he plans to pursue a career in sports medicine.

“I’m not really looking to it now,” Carrier said. “If you have a goal, or somewhere you want to be, you have to fully invested in that. And I’m all in.”