Pound-for-pound king and unified light heavyweight world titleholder Andre Ward said in a statement on his website that he is "leaving" boxing.
"I want to be clear -- I am leaving because my body can no longer put up with the rigors of the sport and therefore my desire to fight is no longer there," the statement said. "If I cannot give my family, my team, and the fans everything that I have, then I should no longer be fighting."
On Thursday, the 33-year-old Ward (32-0, 16 KOs) told First Take more about the thought process behind his decision to retire.
"People see what I do fight night," he said. "They see under the lights, but they don't see the toil, they don't see the grind, they don't see just the pain, the physical pain that you go through, not just in the fights, but to prepare and to get ready for those battles."
He added: "I felt the physicality of the sport -- not just in-the-ring stuff, but the training and the preparation -- start to take its toll on me for the last two or three years, and I bit down and continued to push through. And at this point, it's time, and I know it's time."