Ryan Leaf says he's glad Josh Gordon is stepping away from football to focus on what's really important -- his mental health -- and the ex-QB says he's willing to help if the WR needs him.
Leaf has fought a very public battle with mental illness ... and warns Gordon -- who left the Pats on Thursday to focus on his mental health -- the fight he's facing is a very difficult one to win.
"This will be the hardest thing he ever does," Leaf tells TMZ Sports.