Britain's richest man has not ruled out buying Chelsea Football Club after admitting he did have a tour of their training ground last year.

Jim Ratcliffe was in the Yorkshire Dales on Wednesday to launch Team INEOS after taking over the professional cycling team from Sky.

And while it is understood he has not so far been prepared to meet Roman Abramovich's valuation for the club, believed to be in the region of £4bn despite Chelsea insisting the Russian billionaire has no intention of selling, Ratcliffe hinted he is still interested.

Scroll down for video

Britain's richest man Sir Jim Ratcliffe has refused to rule out him potentially buying Chelsea

Ratcliffe was keen last summer but his valuation was vastly below that of Roman Abramovich

“You never say no, but I don’t know where those conversations will finish..”

I asked Britain’s richest man, Sir Jim Ratcliffe, if he wanted to buy Chelsea FC from Roman Abramovich. Certainly didn’t rule it out.. pic.twitter.com/jNkpzsTGdC — Dan Roan (@danroan) May 1, 2019

He initially dismissed a report in Sportsmail last year that he had been given a tour of Chelsea's Cobham training base, only to then rather mischievously admit the story was true.

And when pressed on Chelsea specifically, he told the BBC: 'I'd never say no, but I don't know where those conversations will finish up.'

There is understood to be interest in Chelsea from different parts of the world, with a bid from Saudi Arabia thought to be serious.

Ratcliffe, however, appears interested in exploring football.

'I am a big Manchester United fan,' he said. 'In fact, I am a tortured Manchester United fan at the moment to be honest.

'We have dipped our toe in the water with football, it's a very different sport, quite a complicated sport, a complicated world.

The 66-year-old is a United fan but watches football at Stamford Bridge - his nearest stadium

Jim Ratcliffe, Chris Froome and Sir Dave Brailsford pose during the Team INEOS unveiling

'We are in the process of learning about it. We bought this club in Switzerland and it has been really educational.

'We haven't got to where we are in the chemicals and business world by being impetuous, rash and stupid.

'We recognised it is a very complex world, we are going through the process of learning and we are not in a desperate hurry to get to the end game.'

Chelsea travelled to Germany on Wednesday for the Europa League semi-final first-leg against Eintracht Frankfurt and manager Maurizio Sarri is coming to terms with a defensive injury crisis.

Frankfurt, 4th in the Bundesliga, represent the sternest test yet of Chelsea's credentials in this competition this season after previously defeating Shakhtar Donetsk, Inter Milan and Benfica.

Antonio Rudiger is out for the rest of the season with a serious knee injury and outcast Gary Cahill did not travel and is also absent through an Achilles injury.

Ratcliffe admitted he did have a tour of Chelsea's training ground in Cobham last year

Manager Maurizio Sarri speaks ahead of Chelsea's Europa League clash in Frankfurt

It leaves Sarri with only David Luiz and Andreas Christensen as established centre-backs for a crucial week that encompasses the two Europa League games and a Premier League match against Watford.

It has also emerged that Chelsea aggravated Rudiger's knee injury by starting him against Manchester United on Sunday. Rudiger had previously been forced off through injury against Liverpool on April 14 and returned a fortnight later at Old Trafford and has now undergone knee surgery in Rome.

Sarri said: 'We tried to arrive at the end of the season, but the injury was there. The meniscus was broken. Sometimes, you are able to do it, to play for one month, but the situation was the same. He was unlucky, but the situation without or with the match was the same. At the end of the season, he would have to have the surgery.'

'Rudi is out at least for three months. I spoke with him yesterday. When you have serious injuries, it's very difficult to remain the same: you can be better or worse. Rudiger is very strong, so I think he will return better than before.'

The Italian added: 'I hope to recover Cahill in one week, but I don't know at the moment. We are in trouble with the centre-backs. In the last two training sessions, we played with Azpilicueta as a centre-back in case. He's the only one who can play there.'