Danish design firm Bjarke Ingels Group (BIG) have revealed the latest changes to their vision for the proposed Howard Terminal Ballpark in Oakland, California.

Set to replace the Brutalist-style Oakland Coliseum, the new sports complex, which will be the home of the Oakland Athletics Major League Baseball (MLB) team, will have a circular instead of jewel box shape in order to "boost fans' experience".

In a statement, Dave Kaval, president of the sports club, said that the restructuring – which includes the creation of a rooftop park with views of the Oakland waterfront – was put forward over the course of meetings with various public officials, fans, and members of the local community.

Details for the 35,000-seat stadium – set to be the smallest arena in MLB – were first proposed last November.

Since then, the project has attracted some controversy, with one scientist at the University of California, Berkeley, warning that the stadium could experience issues with flooding due to its proximity to the Oakland Estuary and California's constantly rising sea levels.

Speaking to Berkeley News, associate professor Kristina Hill, while praising BIG's expertise in "coastal design", said the company would need to brainstorm ways to deal with groundwater.

"It's a tough site," she admitted. "But I can see why they'd want to be downtown and close to the water. I understand that. Dealing with the groundwater won't be easy."

Plans for the building have not yet been finalised, but Oakland Athletics anticipates opening the site in 2023.