Scarlett was injured in Cal's 60-59 win over Washington State on Oct. 4 and has not played since. He was hopeful he could return to action this season but instead underwent surgery and won't return until 2015.
Scarlett had 10 tackles and two sacks in five games this season.
“He’s disappointed obviously,” Cal head coach Sonny Dykes said. “He was really starting to kind of come into his own.”
“He’ll get through it,” Dykes said. “I expect him to have a great year next year.”
Scarlett, a redshirt junior, also missed last season with a broken hand.
After winning just one game in 2013, the Golden Bears are 5-4 this season and attempting to make a bowl for the first time since 2011. They have a bye this week and play USC on Thursday.