NFL's Sam Bradford: I'M ENGAGED ... Marrying Ex-College Golfer!

Another starting NFL quarterback is heading down the aisle ... this time, it's Eagles QB Sam Bradford who's officially engaged to his longtime girlfriend Emma Lavy ... TMZ Sports has learned!

Sources connected to the couple tell us the two have been dating for a few years ... and last week, Bradford popped the question during a romantic dinner at a fancy restaurant.

And get this ... Bradford ain't the only star athlete in the relationship -- Lavy was a pretty damn good golfer at the University of Arkansas, making the SEC All-Freshman Team in 2011!