A warning to Nate Diaz, Conor McGregor has one-punch KO power

Conor McGregor is a bad dude.

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Conor McGregor and Nate Diaz will step into the Octagon on Saturday night for the long-anticipated rematch at 170 pounds.

After getting tapped out in the first fight, McGregor will look to avenge his loss with some heavy-handed shots. And Diaz should take this as a warning — McGregor has one-punch knockout power.

He better not get caught, or he could join Jose Aldo taking a nap on the mat.

McGregor's knockout of Aldo earned him the UFC featherweight championship.