TMZSports.com
Pack up the tin foil hats and UFO paraphernalia ... NFL agent Leigh Steinberg tells TMZ Sports the conspiracy theory that owners blackballed Shedeur Sanders during last weekend's draft is "nonsense."
The former Univ. of Colorado signal-caller, of course, was largely expected to be a first-round pick ... but tumbled all the way to the fifth round on Saturday -- which had people racing to social media to accuse franchises of colluding with one another to keep Deion's son down.

Steinberg, though, told us this week there's just no way that actually happened.