The Yankee fan who ripped a foul ball from Mookie Betts' glove has ties to Rob Gronkowski ... 'cause the Patriots legend says he went to school with the guy!!
The former superstar tight end came to the realization during his appearance on the "Up And Adams Show" ... when he was checking out footage of Austin Capobianco and fellow NYY fan, John Peter, interfering with Betts after he snagged the ball out of the air.
Gronk had an aha moment in real time .