The former running back said the health issue happened out of nowhere on Father's Day, but did not go into detail on what he experienced.

"It was unexpected and served as a reminder of the importance of staying vigilant about our physical well-being, even when we are feeling fine," Barry said in a statement released by the Detroit Lions.

Barry thanked all the medical professionals who helped him out ... adding he's grateful for all they did during the scare.

Barry will be using the experience as a wake-up call ... and will now put more focus on his body and mind.

"Per my doctors' recommendation, I am taking this opportunity to prioritize my health and well-being. I appreciate your understanding and continued support."

Barry is one of the greatest to ever step on the gridiron -- earning MVP honors in 1997. He was named to 10 Pro Bowl teams ... and received the Offensive Player of the Year award twice.

He also has 10 All-Pro selections -- six first-team and four second-team.