The 59-year-old claimed the Spaniard's complaint was "stupid" and he wouldn't "give a s***" about how much his opponents cost, he'd have a job to do for his team.
Speaking to The Times, Southall said: "If I'm playing against Kevin De Bruyne and I'm not as good as him, then I'm going to smash him because that's my job for the team.
"I don't give a s*** how much he cost because my loyalty is to my team. It's no good whingeing.
"What would he do in the same position? Say 'I ain't going to tackle him because he's better than me?'
"I'm surprised there weren't more tackles from Cardiff."