Tom Brady -- Never Messed with Balls In College

Ball pressure was never on Tom Brady's mind back in his college days -- the obsession developed after he got into the pros ... TMZ Sports has learned.

We spoke with Jon Falk, the legendary equipment manager at Michigan during Brady's playing days -- who says he's 100% SURE Brady NEVER screwed around with the balls before a college game.

"At Michigan he never messed around with any footballs because he never got the chance to touch them! That's the way it was, I prided myself on those game balls."

It was a different story for Brady in the pros -- with TB admitting he's maniacal about the PSI of every game ball because he wants to make sure he gets the "perfect grip."

As for Deflategate, Falk says he doesn't believe "Tommy" could be a cheater because back at UM, he was one of the most "standup guys I've ever met. I never saw [him] mess with the footballs."