MUNICH, Germany (Reuters) - Bayern Munich's shock exit from the Champions League earlier this month could be the reason for several training ground bust-ups, coach Ottmar Hitzfeld said on Wednesday.

"It is possible that aggression is coming out because the players have more time to train and have to watch the Champions League games on television," Hitzfeld said.

On Tuesday Ghanaian defender Samuel Kuffour became the second Bayern player in the past few weeks to be fined over a training incident.

Kuffour was involved in a heated argument with team mate Jens Jeremies and allegedly punched Thorsten Fink when he tried to separate the pair.

"Sammy apologised to me so for me the case is over," Fink, who had a bruise under his left eye, said on Wednesday.

Hitzfeld was also keen to play down the incident.

"Sammy lost it," he said. "He's been fined and that's it."

France defender Bixente Lizarazu was also fined for fighting with team mate Niko Kovac earlier this month.

Brazilian striker Elber said tension had crept into Bayern's training sessions since they were eliminated from Europe after finishing bottom of Group G in the first stage of the Champions league behind AC Milan, Deportiov Coruna and RC Lens.

"The training sessions have become almost tougher than the games," he said.

Former Bayern and Germany international Sepp Maier, who now coaches Bayern's goalkeepers, was quick to laugh the incident off.

"Now we're going to hire Vitali Klitschko as assistant coach," he said, referring to the Germany-based Ukrainian heavyweight boxer who is hoping to challenge champion Lennox Lewis for the world title.