Werder defender Mertesacker goes under the knife

Werder Bremen defender Per Mertesacker has undergone a successful operation on the knee injury he picked up at the club's training camp.

The Germany international is still likely to miss the start of the Bundesliga season however after he suffered the injury in training on Tuesday.

Bremen coach Thomas Schaaf revealed new signing Sebastian Prodl could take Mertesacker's place in the back four.

He told the club's official website: 'With him we have got ourselves an important man, who has enriched our team and made it stronger.

'He has demonstrated good commitment and a good attitude; he works hard and seems confident.'