Pinkel, 67, was first diagnosed with the disease in May 2015 and retired after the season that fall. He said a year later that the cancer was in remission, but it now requires treatment once more.
"I'm doing good. I had to get treatment again for the first time in four years. My cancer came out of remission, and so I had treatment last month. I'm doing fine," Pinkel said Sunday. "With my type of lymphoma, you'll never be healed. But that's kind of why I retired when I did -- I just wanted to not go back and regret working 85 hours a week, 35 weeks out of the year when I could be doing other things with my family and my eight grandkids."
Pinkel coached Missouri to 10 bowl appearances in 15 seasons and led the team during the school's move from the Big 12 to the SEC in 2012.
"You keep battling it. I'm going to battle it," Pinkel said. "I've got a very positive approach to it, and I'm around a lot of good people that are helping me. There's a lot of people out there with a lot worse cancers than Gary Pinkel has, and so prayers to all of them."