"American Idol" contestant and former NFL pro Blake Proehl's biggest fan has been revealed -- it's his two-time Super Bowl champ dad, Ricky ... 'cause he tells TMZ Sports his son's singing career has left him speechless!!
Blake -- a star receiver for East Carolina before joining the Minnesota Vikings in 2021 -- has kickstarted quite the second career after transitioning from football ... he's currently crushing it on the popular competition show.
Now that Blake is in the top 24 on "Idol," we talked to Ricky about watching his talented son on the stage instead of the field .