Just 1 day after signing with the Seattle Seahawks, tight end Luke Willson announced he's walking away from football for good ... revealing he was hospitalized with a severe heart condition earlier this year.
31-year-old Willson -- a 2013 5th-round draft pick who won a Super Bowl with the Seahawks in 2014 -- resigned with his old squad on Tuesday.
But, just a day later, the team said they were parting ways with Luke ... without explaining why.
On Wednesday, Willson provided some answers ... explaining he dealt with a serious heart issue a few months ago.
"After signing with the Seahawks yesterday, I have decided to walk away from the game of football," Willson wrote.
"This off-season I went through some health issues and spent numerous days in the hospital with a severe pericardial effusion."
FYI, the Mayo Clinic describes the condition as "the buildup of excess fluid in the sac-like structure around the heart (pericardium)."
If untreated, Pericardial effusion "can lead to heart failure or death," according to Mayo Clinic.
Luke says the medical scare changed the way he views football and life.
"That situation has really challenged me as an individual and changed my perspective on a lot of things with regards to my life. After reflecting on everything yesterday and being in the building, I have decided that it's time for me to begin with the next chapter of my life."
Luke's adult life has been all about football ... so, what's next for the Canadian?
"Football is really all I know. It's all I've done for the last 2 decades. I'll be honest, I have no idea what's next at the moment, but whatever it is, you can be sure that I will bring a lot of energy to it."