VfL Wolfsburg midfielder Kevin De Bruyne has been fined 20,000 euros ($22,644) for his foul-mouthed outburst at a ball boy in their Bundesliga game at Eintracht Frankfurt last week, the German Football Association (DFB) said.

The Belgium international, who is in superb form as Wolfsburg trail only leaders Bayern Munich in the league, demanded the ball for a quick throw-in in an expletive-laden order picked up by stadium microphones.

"The sports court of the DFB has fined Kevin De Bruyne 20,000 euros for unsporting behaviour in the form of extreme sports misconduct," it said.

De Bruyne has apologised to the boy.