To even make the last 16, England need to perform far better than they did against Algeria - universally acknowledged as a pitiful display, even inside the dressing room.
"I certainly felt there was a lack of passion," he said.
"On paper we are a much better team than Algeria but there was no tackling, no-one winning headers, no-one winning second balls.
"It was not acceptable. You have to show a bit of aggression and a bit of fight.
"No player had that fire in their belly. I can assure everyone it is going to be there against Slovenia."