Willie Roaf says he ain't surprised Drew Brees is returning so soon from a punctured lung and broken ribs ... telling TMZ Sports the QB is one of the baddest dudes to ever suit up in the NFL!!
"Drew Brees is probably one of the toughest guys mentally you're going to meet to ever play," Roaf says. "He's focused, he's ultra-competitive and it just motivates him."
Brees busted up his core in back-to-back games just a couple weeks ago ... cracking some ribs against the Bucs on Nov.