Colorado coach Deion Sanders has been ill and out of the office recently, a source confirmed to ESPN on Tuesday.

Sanders has been at his estate in Texas dealing with an “unspecified health issue” as the school’s annual summer football camps began last week, according to a report in USA Today. A timetable for his return is unknown, but on Sunday, his eldest son, Deion Sanders Jr., appeared on a YouTube livestream from the Texas home and said his father was “feeling well.”

“He’ll tell y’all soon enough what he’s going through, what he went through,” Deion Jr. stated, according to USA Today. “When we get back to Boulder, I don’t know. I’m waiting until my dad leaves. When he leaves, then I’ll go. Until then, I’m going to sit here with him.”

Sanders, 57, canceled his speaking engagement scheduled for June 8 in Florida at the Sickle Cell Disease Research and Educational Symposium. The organization posted the update on X:

“Due to an unavoidable last-minute scheduling change, our originally scheduled Foundation Keynote Speaker, Deion Sanders ‘Coach Prime,’ is unable to attend. We are grateful for his support and look forward to future opportunities to welcome him.”

Sanders has dealt with health issues before. In 2022, he had two toes on his left foot amputated because of blood clots that developed from a previous surgery. In 2023, Sanders had a procedure to relieve clots in both of his legs and missed Pac-12 media day.

In late May, Sanders mentioned a health issue in a podcast with former NFL cornerback Asante Samuel, according to USA Today, but didn’t provide details.

Colorado opens the season at home Aug. 29 against Georgia Tech.