Vincent Jefferies Jr. is in his second season an an offensive graduate assistant at Illinois in 2023. Jefferies spent the 2021 season at North Carolina State, working as an offensive assistant before coming to Illinois for the 2022 season. 

Jefferies helped Illinois to an 8-5 record in 2022. The Illini were ranked in the AP Top 25 for five straight weeks, reaching as high as No. 14, and were ranked in the College Football Playoff rankings for the first time in school history. Under the direction first-year offensive coordinator Barry Lunney, the Illinois offense made a leap forward. Illinois' passing offense was the most improved in the nation, as the Illini ranked third in the nation in completion percentage (69.6%), a rise of 122 spots in the national rankings, and All-Big Ten wide receiver Isaiah Williams ranked in the top 10 in the Big Ten in receptions per game (2nd, 6.3), receiving yards (7th, 715), receiving touchdowns (10th, 5), and receiving yards per game (10th, 55). 

Jefferies started his coaching career at the high school level at Garner Magnet in his hometown of Garner, North Carolina. At Garner, Jefferies was the quarterbacks coach and passing game coordinator.

Jefferies finished his playing career at Florida A&M in 2016-17. He was a quarterback and graduated from Florida A&M with a degree in psychology. After graduation, Jefferies participated in the Historically Black Colleges and Universities Spirit of America Bowl where he scored the game winning touchdown.

He also played one season at Santa Rosa Junior College, where he threw for 1,920 yards and 12 touchdowns in 10 games.

Jefferies graduated from Florida A&M's College of Social Sciences, Arts and Humanities with an undergraduate degree in psychology and a cumulative GPA of 3.5. He was a semifinalist for the 2017 William V. Campbell Trophy, the most prestigious academic award in college football.