Illinois projected starting safety Supo Sanni will miss the entire 2010 season after rupturing his right Achilles' tendon in Wednesday's practice, the team announced on Thursday.
"Supo is a great young man who was on track for an outstanding season," Illinois coach Ron Zook said in a statement. "He was really coming into his own, and I was very excited about seeing him play this year. He has a redshirt season available, so he'll still have two years of eligibility once he returns in 2011."
Sanni will have surgery on Thursday.
Illinois' defense ranked worst in the Big Ten last season, allowing 30.2 points per game.
Scott Powers covers high school and college sports for ESPNChicago.com and can be reached at firstname.lastname@example.org.