Former Chelsea star Michael Ballack has taken aim at retiring Bayern Munich captain Philipp Lahm.
Ballack refused to hail his former team-mate, citing a dispute between the pair after the 2010 World Cup in South Africa.
"I got to know Lahm's other face," he told Sport 1 Doppelpass.
"I didn't know that a player who takes on the role of captain doesn't have to give it back afterwards. That was a frontal attack.
"I never made the step back to the national team after that incident. I had no chance to do anything against it. The way it took place was absolutely not okay."