Saquon Barkley has a little bro ... and it's clear freak athletic talent runs in the family!
The top RB in the draft was working out with his high school sophomore brother, Ali Barkley -- and showing off their insane bounce.
Ali crushed a box jump that looked like it was over 4 feet tall -- and then Saquon 1-upped him ... by doing a freakin' ninja jump OVER the boxes!
In case you're wondering, Ali is 5'11", 190 lbs and will be a junior RB at Whitehall HS in PA this fall (class of 2020).