Former UFC title contender Chael Sonnen has a feeling that Michael Bisping has already retired from the sport.

Bisping was expected to have his retirement fight in the main event of UFC London, which is set to take place on 18 March at the O2 Arena, with talks of a potential bout with former light heavyweight champion Rashad Evans.

However, the Briton later revealed on Twitter that he is not taking part in the event anymore, having spoken with the UFC.

In fact, the former middleweight champion had hinted at retirement even before his UFC 217 loss to Georges-St Pierre back in November last year.

Following the loss of his title, Bisping would go on to have a quick three-week turnaround to fill in for Anderson Silva as Kelvin Gastelum's opponent at UFC Shanghai, only to be knocked out in the first round.

With the UFC – as of now – only going to England once a year, Sonnen thinks the fact that Bisping is not fighting in his native homeland next month could mean that he has already retired.

"Is Michael Bisping done? I feel like he kind of just retired today," Sonnen said on his official YouTube channel. "I would be very disappointed if he was done but he had said at one point, before he even fought Georges, he said, 'I'm going to do this fight with Georges and then I'm going to fight in England and that's going to be my farewell.'

"So he had the Georges fight, he ended up fighting Kelvin in addition to that but it was still 'I'm done after England' and he's now come out officially and said, 'I am not fighting in England.' If you piece everything together, I'm sitting back, going, 'Wait a minute, did he just retire then?'

"I don't know when the UFC is going back to England. Maybe the England thing isn't as important to him but I'm just going off of his own words and I think Michael Bisping might have retired, which I don't want to be true."

Bisping (30-9 record in MMA) achieved his life-long dream when he defeated Luke Rockhold at UFC 199 in June 2016 to become the middleweight champion.

The 38-year-old would go on to avenge his loss to Dan Henderson in his first title defence at UFC 204 before losing the belt to St-Pierre at Madison Square Garden in New York.