James DeGale has announced that he will undergo surgery on his shoulder which could potentially rule him out until the end of 2017.

The IBF super-middleweight champion has not fought since January, but he had been expected to make the next defence of his title at London's O2 Arena on September 3.

However, it has now been revealed that he may be sidelined until the final months of the year after the decision was made to undergo an operation on an injury that he says he first suffered early last year.

The 31-year-old is quoted by The Mirror as saying: "I will have surgery on my right shoulder that will mean I will be out of the ring for a while.

"I suffered the injury several weeks before I fought Rogelio Medina 12 months ago but decided to fight through the pain, as I did earlier this year against Badou Jack. I was only operating at 60 to 70 per cent however and that showed against Jack – I only threw seven jabs in that fight and I wasn't able to throw a hook.

"My arm will be in a sling for a few days and I'll be given exercises to do on my own. A few weeks later, I'll start my rehab with my physio and within eight to ten weeks I should be able to spar. I will definitely be able to fight before the end of the year."

DeGale had hoped to face Callum Smith in July - before deciding to have surgery - but WBC mandatory challenger Smith will face Anthony Dirrell for a vacant world title in September.