Podolski clashed with the Germany skipper in Wednesday's 2-0 win over Wales, but the German Football Association (DFB) have played down the importance of the incident, claiming it was dealt with internally.

However, Beckenbauer believes that by letting Podolski off the hook, a precedent has been set which could unsettle the national team.

"It seems to be boiling over internally and something has clearly been building up and exploded," he said.

"Ballack has got to watch out if young players are already resorting to such measures."

Podolski yesterday apologised publicly for making a mistake and donated 5,000 euros to a charitable organisation, but the lack of a clear condemnation of his actions on behalf of the DFB has surprised Beckenbauer.

"You cannot just let Lukas Podolski's slap go," he wrote in his Bild newspaper column.

"Coach Joachim Low and the coaching team have got to protect the captain above everything.

"If you can clip Michael Ballack round the ear and get away with it, then that is hardly the right signal."

Beckenbauer is demanding more respect for Ballack and remembers back to when he was Germany captain and enjoyed a strong, authoritative influence on his team-mates.

He said: "In the 1974 World Cup, I clashed with Uli Hoeness and made my opinion clear to him.

"The words back then were perhaps even stronger than today.

"Uli would never have seriously contemplated smacking me. After our exchange, Uli played better and we won the World Cup."

Ballack's status as captain has been cast into doubt since he criticised Low last year for the way he treated the older players.

He also complained about a lack of discipline during Euro 2008 when many of his team-mates spent afternoons relaxing by the swimming pool with their wives or girlfriends, ridiculing general manager Oliver Bierhoff's organisation skills.

Although he publicly apologised to both, he may not yet have ironed out his differences with some of his national team colleagues and Podolski's reaction is being seen as evidence that the Chelsea midfielder is not totally accepted as their leader.