"There was a lot of tension and emotion on the pitch, it was a big match and we clashed," Drogba told L'Equipe. "These things happen and five minutes later, everything was forgotten.
"Ballack is someone I really appreciate, as a player and as a man. He has had to work really hard this season but he has come back very strong.
"He is making the difference. He is Chelsea's most important player at the moment."