Duff’s operation is the 13th for the club this season and while the Magpies believe it has been a success and are hoping he could be ready to resume early in the new season, the word from Dublin, where he is recuperating, is not so positive.

Reports from Ireland suggest the former Blackburn and Chelsea midfielder could be out of action for six months, and that would come as a major blow as Newcastle attempt to bounce back from a difficult campaign.

A club statement said: “Damien Duff has undergone a foot operation following the injury sustained during Newcastle United’s game at Portsmouth on April 14.

“The Republic of Ireland international has been sidelined since the game at Fratton Park, but underwent surgery on his injured right foot last Friday.

“The operation was a success, and left-winger Duff is now recuperating back in Dublin.”

It is Duff’s second operation of the season after he underwent a procedure to repair damaged knee cartilage.

He (Duff) has struggled to make the impact he was expected to in his first campaign at St James’ Park after Glenn Roeder swooped to bring him back north last summer.

He was signed as an out-and-out winger, but has at times had to play as a striker and at left-back as injuries have decimated the squad.

Newcastle are currently in the process of recruiting Roeder’s successor following his resignation last Sunday with Sam Allardyce in pole position.

But whoever eventually lands the job will be keen to have Duff back at his disposal as quickly as possible.