Philadelphia Eagles legend Jeremiah Trotter tells TMZ Sports he's training his Clemson football commit son to be a BEAST ... saying the kid is going to better than him!!!

"He's more athletic than I was," Jeremiah says. "He's faster than I was ... he's better in space than I was."

FYI, Jeremiah ain't blowing smoke ... his son, Jeremiah Trotter Jr., is a nationally ranked linebacker in the 2021 class who's already 6 feet, 210 pounds.

And, Jeremiah Sr. tells us he thinks Swinney is going to LOVE the kid once he gets to Clemson's campus in a couple years ... saying the Tigers coach is "getting a killer, man!"

"Since he was young, I mean this kid, I just tell all my friends this guy will run through a brick wall," Trotter says ... "he covers like a DB but he hits like an old-school, physical linebacker."