McDermott threw for 2,367 yards, 25 touchdowns and 12 interceptions during his junior season, completing 67.3 percent of his passes. He also rushed for 260 yards and three touchdowns on 77 carries, averaging 3.4 yards per carry.
Allen Trieu, a 247Sports recruiting analyst, referred to McDermott as one of the top quarterbacks at the Carolina eXperience Prep Football Showcase in August.
"Sully was very accomplished at this event, displaying down-the-field accuracy on the deep ball, great timing and tempo on the quick game and the ability to move well during the bag drills," Trieu wrote at the time. "We expect to see this kid playing on Saturdays in the near future."