Defending champions England take on New Zealand in the opening game of the Cricket World Cup on Thursday at the start of a marathon tournament which could dictate the event's place in the future of the sport.

With the explosion of Twenty20 cricket both in global events and lucrative franchises, the prospects of the 50-over game have been clouded in uncertainty.

Now, the format is facing the biggest crisis of confidence in its 52-year history.

"We believe strongly that ODIs should be World Cups only," Mark Nicholas, the new president of the MCC, the body responsible for the laws of the game, told ESPNcricinfo.

"We think it's difficult bilaterally now to justify them. They're not filling grounds in a lot of countries. And there is a power at the moment to T20 cricket that is almost supernatural."

He added: "In a free market, the most money wins. And that's just the end-game."

The 50-over format is viewed as too pedestrian in the slipstream of the high velocity, smash-and-grab Twenty20.

"The ODI has been reduced to virtually depending on a World Cup year for its importance," wrote former Australia captain Ian Chappell.

This year's World Cup has only 10 teams but will take 45 days to complete.

The Twenty20 World Cup in the United States and West Indies in 2024 will see 20 nations compete in an event condensed into four weeks.

Furthermore, the short-form game is widely expected to be voted in as an Olympic sport for 2028 next week.

New Zealand skipper Kane Williamson, however, sees room for T20 and 50-over cricket to co-exist.

"The ODI World Cup is definitely one of the top events that we can play and be involved in," he said.

Meanwhile, England skipper Jos Buttler, who leads his side into action at the world's biggest cricket arena, the 132 000-capacity Narendra Modi Stadium in Ahmedabad on Thursday, says his team is under no pressure to retain the title.

"We are not feeling like we're defending anything," he said.

"We're all starting in the same place and have big dreams and ambitions of going all the way."

- Stokes injury -

England are set to be without superstar batsman Ben Stokes for the game due to a hip injury.

New Zealand, runners-up at the last two World Cups, are missing Williamson, still recovering from a knee injury.

"Fingers crossed he's on the park sooner rather than later," said stand-in captain Tom Latham.

Veteran seamer Tim Southee is also sidelined, yet to recover from a dislocated thumb.

The tournament sees Pakistan visiting India for the first time in seven years after an intense spell of brinkmanship which almost saw them boycott the World Cup.

Babar Azam's team only received visas two days before they were due to arrive at their base in Hyderabad where their first warm-up game was played behind closed doors.

Security fears over their blockbuster clash with bitter rivals India next week meant the game was brought forward a day.

That in turn caused a domino effect of nine rescheduled matches in total.

"I think the way people are responding towards our team, everyone enjoyed it. We are a week in Hyderabad so it is not like we are in India, it is like we are home," said Azam on his first trip to the country.

- 'Half the world watching' -

Despite the troubled build-up, even opposing skippers are looking forward to the October 14 epic between the two rivals.

"I don't think there's too many events around the world where you feel like half the world's tuning in to watch whenever India play Pakistan in a World Cup," said Australia skipper Pat Cummins.

India were champions the last time the tournament was staged on the sub-continent in 2011.

With the Asia Cup recently secured and with the likes of superstar batsman Virat Kohli, who is just three centuries short of 50 in the ODI format, in their ranks, India are one of the major favourites to win a third title.

However, Australia, with the senior batting skills of David Warner and Steve Smith to call upon, will also be in the mix for a sixth world title.

Under the tournament format, all 10 teams play each other once with the top four heading for the semifinals.

The final takes place in Ahmedabad on November 19.