Haynes lettered 3 years at Bowie High School in Maryland and was a two-time captain who started 3 years on the offensive line. He played in Maryland’s annual All-Star game, the Maryland Crab Bowl in 2017. He was not heavily recruited and decided to play football at the University of Connecticut after his senior season.
Haynes redshirted in 2018 after only playing sparingly in 2 games for the Huskies. In 2019, Haynes became a mainstay on the UCONN offensive line starting in 12 games and showing flashes of being a future star on the line.
The 2020 Connecticut football season was canceled. In 2021, Haynes started all 12 games and became the undoubted leader of the Huskies offensive line. Last season was his breakthrough season, and he started all 13 games at guard to became just the 3rd Husky in the FBS era to earn All-American honors after being named to the Sporting News and Associated Press All-American teams.
Entering the 2023 season, Haynes was named a preseason Sporting News first team All-American. He started 12 games for the Huskies and was one of the better rated guards in the country. He was name AP All-American for the 2nd straight season.