The group has signed the "western orange" Chet Atkins 6120 model, known as a Gretsch Country Gentleman, and the instrument has been posted on auction website eBay.

Gossard has not offered more details about the identity of his friend or why he or she is in rehab.

The winning bidder will also receive a handwritten note from the guitarist and an additional authentication letter from George Webb, Pearl Jam’s longtime equipment manager.

The Alive hitmaker has owned and played the guitar for "15-20 years".

Current bidding on the guitar has reached over $14,000 (£11,200).