The Blink-182 drummer made a surprise appearance on stage alongside Machine Gun Kelly in Los Angeles on Wednesday night as part of the rapper’s Mainstream Sellout Tour.

The pair played two tracks together: Bloody Valentine and Tickets to My Downfall.

The musician reportedly told fans that he had grown up “idolising” Barker, before introducing him.

It comes barely two weeks after the drummer was admitted to the Cedars-Sinai Medical Centre in LA to be treated for “severe life-threatening pancreatitis”.

His wife, reality star Kourtney Kardashian, was pictured entering the facility with him and was also at the concert on Wednesday.

The Hollywood power couple staged a “practice wedding” in Las Vegas in April, and announced they had legally wed at a courthouse in Santa Barbara, California, in May.

They later hosted an extravagant ceremony for friends and family in Portofino in north-west Italy.