To the text, the 31-year-old has posted a video from the gym where he writes that he has been denied work for 889 days.
Earlier this year, Kaepernick and the NFL reached a deal after he felt he was being kept away from the NFL because of his stance on injustice. He was criticized, among other things, by President Donald Trump, who wanted to introduce a knee-jerk penalty.
The NFL season begins in September.