Chuck Liddell has a challenge for Floyd Mayweather -- you really wanna make a statement? Don't run from Conor McGregor ... KNOCK HIM OUT! 

The Iceman was out in Calabasas when he said he'd love to see Floyd really take the fight to Conor in a real-deal brawl. But he knows Floyd probably has less exciting plans ... 

"I don't think Floyd will come after him. Floyd will be happy making the money and running around."

Not so fast ... Floyd's dad says the boxer has some "presents" for Conor and plans on "whooping his ass."

We'll find out on August 26 ...