Barnes grew up in Covington, Kentucky and attended Holy Cross High School, where he played basketball and ran track in addition to playing linebacker and running back on the football team, coached by former Cincinnati Bengal, Bruce Kozerski.
[1] As a senior, he was named first-team All-State and the Class 2-A, District Six Player of the Year after leading the team with 126 tackles on defense and rushing for 1,567 yards and 22 touchdowns on 150 carries on offense.
[6] He stayed as a pass rusher during his junior season and finished the year tied for the second most sacks on the team with 7.5 along with 11.0 tackles for loss.
[15] On January 7, 2025, head coach Dan Campbell announced that Barnes would miss the remainder of the season.
[16] During the 11th Annual NFL Honors on February 10, 2022, NFL veteran and 2021 Walter Payton NFL Man of the Year Award winner Andrew Whitworth told a story about himself and Barnes reuniting after a 2021 Week 7 game between the Los Angeles Rams and Lions; Barnes approached Whitworth after the game to thank him for his earlier mentorship through Boys & Girls Clubs of Greater Cincinnati.