Drew Brees WILL come back from the firestorm he's currently in ... so says Nate Boyer, who tells TMZ Sports, "There's people that have done way, way worse things."

"And, it's not even like he really did anything bad," Boyer says. "He just misspoke, I think."

You'll recall ... Boyer, a retired Green Beret and former NFL player, was the one who helped convince Colin Kaepernick to kneel -- rather than sit -- for protests during national anthems.