Pezzoni attacked during carnival

Pezzoni will undergo an operation to reset the nose on Thursday, the Bundesliga club said. He will receive a special mask to allow him to train, though Cologne said a precise date for his return can only be determined after the surgery.

He is unlikely to play in this weekend's local derby at home to Bayer Leverkusen.

Media reported that Pezzoni was struck in the face on Sunday without provocation by an unknown assailant in Huerth, a town bordering Cologne.

"I just stood there as someone tipped me from behind ... Then I got hit in the face without warning," Pezzoni told the Cologne-based Express newspaper.

Cologne coach Stale Solbakken said he was 'stunned' and 'sorry for the lad'.

"I just spoke with him and know he didn't drink any alcohol and was near his home," Solbakken said. "What can he do against such an attack? "

Another defender, Miso Brecko, was fined by Cologne for crashing his car while driving under the influence as the carnival celebrations began last week.

"I give the players a lot of freedom. But they must prove they can deal with it, or if I'm overseeing a kindergarten here," Solbakken said.