MANCHESTER, England (AP) — The race is on to buy Manchester United and it will take deep pockets to meet an estimated price of $6 billion.

No wonder the oil and gas rich state of Qatar is being so heavily linked with a bid and Elon Musk’s name refuses to go away despite the Tesla owner saying he was joking when writing on Twitter last year about his intention to swoop in for the Premier League club.

With a declaration of interest expected to be made by Friday, only one potential buyer has gone public so far. Jim Ratcliffe, the billionaire owner of petrochemicals giant INEOS and one of Britain’s richest people, announced his intention to bid last month.

Other confirmed candidates have been quiet, though that is likely to change after Friday.

Merchant bank Raine Group is handling the process a year after overseeing the sale of Chelsea, which commanded the biggest ever price for a soccer team when bought for $3 billion by a consortium led by Todd Boehly and Clearlake Capital.

That price was driven up by interest from around the world, with US-based bidders particularly eager to take control of one of the biggest clubs in the world and gain a stake in soccer’s most popular league.

Chicago Cubs owner the Ricketts family, Boston Celtics part-owner Steve Pagliuca and New York Jets owner Woody Johnson were all in contention, while there was also a reported bid from Saudi Arabia, as well as British-based interest.

With United anticipated to command double the price of Chelsea, the shortlist of serious buyers is likely to be even more exclusive.

Ratcliffe declared himself a contender despite stating last year that he had dropped all interest in owning a Premier League club after missing out on Chelsea and being given little encouragement from the Glazer family, the current American owners.

That all changed, however, when the Glazers, who also own the NFL’s Tampa Bay Buccaneers, announced in November that it was pursuing outside funding. While that has led to speculation about who could afford to buy out the family, 18 years after late patriarch Malcolm Glazer bought United, partial investment has also been explored.

It is uncertain, however, if investors would be willing to inject the sort of funds that may be required to build a new stadium without having overall control of the club.

The cost of redeveloping or rebuilding United’s iconic Old Trafford stadium is widely considered to be a key reason why the Glazers are willing to sell after long-resisting campaigns from fans to drive them out. It could cost in excess of $1 billion to build a new stadium.

The club’s training ground could also require investment, as well as a squad that has been unable to keep pace with rival Manchester City, which is owned by Abu Dhabi’s ruling family.

A sovereign wealth fund has long-been considered a likely bidder and reported interest from Qatar has gathered pace in recent weeks. The Gulf country already backs Paris Saint-Germain through Qatar Sports Investments and any bid for United would have to come from a separate entity to meet UEFA ownership rules on teams competing in the same tournament.

According to reports, a buyout of United would come from the Qatar Investment Authority.

If a bid comes from Qatar, then Ratcliffe, a boyhood United fan and said to be worth $15.1 billion, would face a considerable challenge to compete.

It’s a different story for Musk, however, who is said to be worth $187.2 billion.