"I am devastated and heartbroken for Karl," coach Dana Holgorsen said in a statement. "He is a young man who has given everything he has to our football program and university over the past four years and who elected to return to WVU for his senior season to earn his degree and to be a part of something special with this team.
"He exemplifies what it means to be a Mountaineer. Karl is an All-American, a fierce competitor, a leader and I know he will have a full recovery, and I can't wait to watch him on Sundays next fall."
Joseph's five interceptions this season -- three came in the season opener against Georgia Southern -- were tied with three others for the lead in the FBS. A four-year starter, he was also on pace to set a school record for career defensive starts.
He developed a reputation for being one of the hardest hitters in all of college football as the enforcer of the Mountaineers' secondary.
"I want to thank my teammates and my coaches for their outpouring of support," Joseph said. "This has been difficult for me and my family, but I know I will come through this stronger than ever. I will forever be a Mountaineer and will be cheering on our team every step of the way."
West Virginia hosts No. 21 Oklahoma State this weekend.