This is the best, worst version of a Lady Gaga song you'll ever hear ... courtesy of retired (?) NFL superstar Rob Gronkowski!!
The 30-year-old had some time to kill backstage before his appearance on "The Kelly Clarkson Show" ... so he tasked himself with the VERY tough 2011 Gaga hit, "You and I," to show off his pipes.
And, MAN!! Did we mention this guy is great at football??
Look ... it's not an easy one to pull off. It's like one of those songs only Mother Monster can pull off, so don't sweat it, Gronk.