Even one of the most famous athletes on the planet can geek out over celebrities -- 'cause Aaron Rodgers was giddy as hell after meeting Liev Schreiber at New York Jets camp ... calling him the "f***ing voice of God!!"
The "Ray Donovan" actor/"Hard Knocks" narrator made a rare appearance on the HBO series Tuesday night ... dropping in via helicopter to hang out with the team during practice.
The most excited player was easily Rodgers ... who told Liev he's a huge fan of his filmography.