Bayern Munich chairman Karl-Heinz Rummenigge has told Manchester United to stop contacting the Bundesliga giants over the availability of Thomas Muller.
The Red Devils have been heavily linked with the German World Cup winner for some time, but so far, Bayern have refused to entertain an offer.
Despite Bayern's stance, Rummenigge has suggested that United have failed to give up their pursuit, but he insists that they are wasting their time.
"I am not a banker, we are a football club," Sport1 quotes Rummenigge as saying. "That is why we never even considered selling Thomas Muller.
"I told my colleagues at Manchester United: 'I cannot close down my email account, but you no longer need to send me anything. It is useless."
Muller is tied down to the German club until 2019.