Steve Cohen, if he buys the Mets for a $2.6 billion valuation, is expected to have a chance to develop Willets Point, possibly the largest vacant site in the five boroughs, two sources close to the situation said.

The Wilpons have plans to develop the 61-acre site in Flushing with Stephen Ross’ Related Companies.

Cohen and Ross are said to be friends.

Mayor Bill de Blasio in 2018 reached an agreement with the Wilpons to create 1,100 units of affordable housing at Willets Point by 2022 on a city-owned tract, as well as a new public-school building.

However, plans for much of the first phase are still being worked out.

Willets Point is adjacent to Citi Field.

Citi Field itself is owned by New York City. The Mets and Cohen would own the operating company that manages the ballpark.

The city has paid more than $280 million to acquire and clean up much of Willets Point, which formerly contained junkyards and auto-repair and manufacturing shops.

The Islanders in 2016 were speaking with the Mets about building a hockey arena in Willets Point. As it turned out, the Isles are now planning to build an arena at Belmont Park.

There were plans when Mike Bloomberg was mayor to build a 1 million square-foot mall in Willets Point.

The Mets declined comment.