Abrams sustained the injury during preseason workouts. He will redshirt this season and be able to return in 2015-16 for his final season of eligibility.
A Chicago native, the point guard started all 35 games for the Fighting Illini last season, averaging 10.7 points and 3.5 rebounds and leading the team in assists.
"Tracy worked hard in the offseason to put himself in great position heading into his senior year, so he's obviously disappointed and we are for him as well," coach John Groce said. "But Tracy personifies toughness; he has the heart of a champion and I know that he will only come back stronger from this experience when he returns to the court next year."
Illinois went 20-15 last season and finished in eighth place in the Big Ten.
- Molly Geary