Michael Irvin Says He's Bigger Than Justin Bieber ... Where It Counts

Yep, that headline is a direct reference to Michael Irvin's junk.

We were talking with the Playmaker about celebrity underwear endorsers (yeah, it was a weird convo) ... when we brought up guys like Justin Bieber, who's a spokesperson for Calvin Klein undies.

That's when Irvin told us point-blank he couldn't rock the same drawers as JB because of ... well ... junk size.

"Those are small guys. I may not be able to fit in their underwear ... if you know what I mean."

Bold statement considering the whole "Bieber's Got a Huge Penis" revelation of 2015 (remember that?).