Charlie Sheen has slammed John Mayer for naming the actor’s close friend in a new lawsuit.

TMZ reported earlier this week the 36-year-old singer had filed suit against watch dealer Robert Maron, claiming he was sold Rolexes with counterfeit parts.

But Charlie told the website on Thursday his pal couldn’t be more of a stand-up guy and suggested John simply has a case of buyer’s remorse despite allegedly turning a profit on the timepieces.

"Wait!! Mayer spent $5 million with Maron and is crying about $600K?!? Ask him how he did on the $4.4 million... Sorry that seven of your 100 watches aren't to your liking! boohoo!!" Charlie said.

"Maron wrote the book - period the end,” Charlie added. “Nothing but respect for Bob - his integrity is beyond reproach!”

In legal documents obtained by TMZ, John reportedly claims he was defrauded by the defendant after the pair met in 2007.

John alleges he purchased multiple watches from Robert but in 2010 was told one of the pieces was “not authentic in all respects” after he sent it to the manufacturer for repair.

Robert reportedly labelled the incident an “isolated event”, and gave John a credit.

The singer claims the following year he was informed by Rolex at least seven of his watches were counterfeit, according to the website.

He is reportedly seeking a refund for the seven watches in question in the amount of $656,000.

John was apparently satisfied with other watches purchased from the defendant.

Spokespersons for the parties had not commented publicly on the matter at press time.