He was a Big 12 honorable mention all-conference linebacker in his first season at the position and was focused on graduating in May with a degree in Interdisciplinary Studies.
But he wasn't just focused on schoolwork, Barnes was dedicating himself in the weight room to prepare for a possible call to the NFL.
Although it was a longshot, Barnes just wanted a chance to see what he could do against the greatest football players in the world.
"I just want to get invited to a camp, anybody's camp, and go out and show what I can do," said Barnes last January. "Nobody really knows about me. But there's been a lot of people make it at the next level that nobody has heard of. Hopefully I can be that guy. All I need is the opportunity."
Barnes' hopes became reality when the Washington Redskins signed him to a two-year contract as an unrestricted free agent on Oct. 5 to the league's base salary.
He is the first Sikeston athlete to make the NFL since former Tampa Bay Buccaneer great James Wilder in 1981.
Barnes, 23, appeared in 12 games and recorded seven tackles while serving as a backup middle linebacker and a special teams player.
While his playing time was limited, just getting the call to the NFL was a dream come true.
"I was thinking practice squad because I had just gotten there," said Barnes. "But they signed me to the active roster. There was no hesitation to sign. I was very surprised. I was just going for the practice squad but when they said active roster, I'm smiling from ear to ear."
Barnes actually went through training camp with the Baltimore Ravens, who did eventually sign him to the practice squad.
Barnes spent a couple weeks with them and participated in their preseason games, including one that was nationally televised on ESPN.
"That was a thrilling time," said Barnes. "I'm sitting there thinking, 'I can't believe I'm here -- playing in the NFL.' I know it was preseason, but it was nerve-racking at times because you don't know if you're going to be cut the next day."
Barnes was released from the Ravens to clear room for players such as Deion Sanders.
Barnes then came home before getting a call to come work out for Green Bay. The day his flight was to leave, he got another call to return to Baltimore to sign with the practice squad.
Barnes headed back to Baltimore where he spent another week with the Ravens.
They released him again, but he wasn't unemployed for long.
He worked out for Green Bay, spent another week at home, and then he got the call from the Redskins.
He went through a workout and Washington signed him to the active roster.
Barnes made his NFL debut on Oct. 10 against Baltimore, the team that had just released him.
"It was exhilarating -- it was an honor to be out there," said Barnes. "I went from watching it on TV to being out there and being watched."
And making it even more special, was the fact that he was playing against some old teammates for the Ravens, including All-Pro linebacker Ray Lewis, who he'd spent time with during camp.
"Everybody knew I was over there," said Barnes. "I had called a buddy of mine and told them and they were congratulating me. We talked a little bit on the field and they would say something back. It was fun. I was sitting there on the sideline when our offense was on the field and Baltimore's defense was out there and then Ray and some of those guys looked over at me and start ed smiling. It was a great time."
Former Sikeston High School coach Charlie Vickery said he tuned in every time Washington was on TV, scanning the screen for Barnes' No. 51 jersey.
"I thought that was just awesome," said Vickery. "Every time Washington was on TV I was watching. I can't imagine what he and his family was feeling. Everybody is so proud of him. He's worked to get there. He had the physical ability to do it, but he worked hard to get there and he's a great kid, even though he's not a kid anymore. It should make everybody in the whole town and school proud of him because he's really done well.
Barnes looks anything but the long, lean athlete that scored touchdowns for the Sikeston Bulldogs.
The 1999 high school graduate was listed at 6-foot-4, 200 pounds as an all-state defensive back. In the NFL, he is officially listed at 6-2, 247 pounds. NFL players are measured without shoes.
With the added weight, Barnes' speed has dropped some, but not much. He says he can still run in the 4.5 to low 4.6 range in the 40-yard dash.
"Number one, Brandon's always had the physical frame," said Vickery. "He's tall and had the speed and he just worked extremely hard to make himself into what he is today. He's going to work hard and stay in shape and do what he can to keep his speed. Obviously you're going to lose a little bit at that size, but for a linebacker running in the 4.5s or low 4.6 range, that's awful good for weighing almost 250 pounds."
While Barnes never had eye-popping statistics in high school, Vickery said he always had a "linebacker" mentality for his Bulldogs.
"You wouldn't have thought he would be a linebacker, but he always loved to hit," said Vickery. "You could watch him on the films and highlights -- we might have an interception or a pass completion that he wasn't involved in, and he'd turn around and make some of the most awesome blocks out there. And defensively he was always a great hitter. He ran so well, being 6-4 or 6-3 1/2 and he was about 205 in high school. He could've played anywhere for us."
Barnes played free safety and wide receiver for Vickery's Bulldogs. Mizzou recruited Barnes as an athlete and had him pegged as a wide receiver from the start.
After three years at receiver, including a redshirt year, Barnes was moved to the defense to help out the secondary. He had a successful stint as the free safety but coach Gary Pinkel still liked his potential as a linebacker, which is where he ended up for his final year.
"When they moved him to linebacker I really wasn't for sure that he was big enough," said Vickery. "But he had the heart and physical prowess to do it. Once he moved there he just got better and better and I think that's going to prove the same in the pros."
Barnes played at 230 pounds for the Tigers his senior year and Pinkel thought he needed to added five or 10 pounds to play.
Barnes actually got up to 250 for training camp in Baltimore before settling back down to his current 245.
But having the physical ability to play in the NFL doesn't cut it. There is so much more involved, according to Barnes.
"Learning the offense and learning what they do, that's the hardest part right now," said Barnes. "I got my opportunity and I had to learn it on the run. It was one of the toughest defenses I've ever been in as far as learning adjustments. I play the Mike, which is the quarterback of the defense. In my position, we get the signal and call out the play. If the offense does anything, then I make the adjustments and call out the fronts. The safeties call out the coverages, but we do most of the calls."
The Redskins were a disappointment this past season in legendary coach Joe Gibbs' return to the team. They finished 6-10, but the team's defense was ranked third in the NFC.
Barnes said he will report to Washington's mini-camp March 21.
Even though Barnes signed a two-year deal, he said there's nothing for sure in the NFL.
"You're never set," said Barnes. "They expect me to be back there in shape and part of the team, but nothing's guaranteed in this league."
While he was bouncing around from team to team, Barnes said he never considered quitting, but he was wondering about a job if he couldn't make the NFL.
"I never thought about quitting," said Barnes. "I just needed to keep working, but at the same time I was thinking of what to do if things didn't work out. I was going to give it a couple years."
Barnes was recently back in Sikeston and he spoke to the basketball team.
"I went by the school and talked to the team," said Barnes. "I just told them not to quit and fight through adversity. I told them to separate themselves from bad influences. Listen to the coaches and you can make it. Stay off the streets and make grades. That's the first priority."
In addition to his NFL exploits, Barnes is about to embark on another journey as he is set to get married on July 2.
Yes, it's a busy time for one of Sikeston's greatest athletes.
Barnes says he's not content with being just a special teams player or a backup linebacker.
He says his ultimate goal is to be a starter and to have a long career.
"He's just scratched the surface at linebacker because he's played wide receiver and defensive back his whole career," said Vickery. "At Mizzou they moved him to linebacker his last year, so he's only been at that position for two years.
He's skilled enough, he's tough enough and he's smart enough to get better every day. If he gets the opportunity, I think you'll see him in the NFL for several years. Hopefully that will come about."