German legends Lothar Matthaus and Stefan Effenberg are trading insults over Per Mertesacker's Arsenal academy plans.

The Gunners captain will retire at the end of the season and take charge of the academy.

Mertesacker upset Matthaus when stating he was already prepared to hang up the boots.

"He has the idea to work in the youth. How does he want to convey this professionalism to a young player when he says that there is too much pressure? That will not do," rapped Matthaus.

But Effenberg countered: "I believe that Lothar Matthäus has a huge problem with youth academies because he does not understand it. Or do not want to understand. That can only be because he has not really dealt with the subject.

"Of course Mertesacker can do the job - and in an outstanding way. He knows what he's talking about."