"He's a hell of a force," Gustafsson said.
He saw what the fighter nicknamed "Rumble" did to Antonio Rogerio Nogueira last summer, after all. For that matter, Johnson has treated nearly everyone who's stepped in the cage with him over his past eight fights, all of which he's won, with five knockouts along the way.
But that doesn't mean the Alliance MMA fighter is going to feel any fear when the duo square off on Saturday in the main event of UFC on FOX 14 in Stockholm, Sweden, in front of an expected crowd of 30,000.
The way Gustafsson sees, it, he's a well-rounded fighter, while Johnson remains a one-punch threat.
"He's one-dimensional," Gustafsson (16-2) recently told reporters. "Doesn't move a lot. Comes in hard, throws the left kick, left hook, straight right. I'm not afraid of his wrestling at all. I'll cover my face up, not going to let him hit me. I need to bring my ‘A' game and I will."
Johnson (18-4), for his part, seemed to anticipate the style critique when he spoke to reporters back at the "Time is Now" media event in Las Vegas.
"Let him think power is all I have," Johnson said. "I have been working to improve my game as an all-around fighter and if someone still wants to think that's all I've got at this stage of the game, they're going to be in for a surprise."
Gustafsson, though, is sticking to his guns.
"I'm a better fighter than Rumble," he said. "I've got too many tools for him."