KANSAS CITY, Mo. -- MLB commissioner Rob Manfred threw his support behind a new stadium for the Royals on Wednesday, calling both of their potential sites near downtown Kansas City "unbelievably high quality" for the type of revenue-producing, multi-use districts that are necessary for small-market clubs to compete.

Manfred spoke for an hour at the Urban Youth Academy, which is designed to encourage inner-city youth in baseball, alongside Royals chairman John Sherman and Bob Kendrick, the president of the nearby Negro Leagues Baseball Museum.

The Royals plan to announce in September whether they will build a replacement for Kauffman Stadium in the East Village, an area near the T-Mobile Center and the existing Power & Light District, or across the Missouri River in Clay County, where there is more land available for a potentially larger baseball village.

"This is a tremendous opportunity for this community -- forget the Royals," Manfred said. "Either of these sites are outstanding sites for a new ballpark. Either present the opportunity for entertainment district development around the ballpark.

"I think in our economic system, new facilities provide a ballclub with an opportunity for revenue generation that simply doesn't exist in older footprints. At some point -- great ballpark here, but having said that, it is an older ballpark that does not have the kind of premier revenue-generating opportunities that you get in a new facility for a market this size."

The Royals have said the new ballpark project will cost about $2 billion. Most will be privately funded, but a portion of the money is expected to come from the renewal of a 3/8-cent sales tax that has been used the upkeep of Kauffman Stadium.

However, the sales tax was passed by voters in Jackson County, which is where the downtown ballpark location sits; if that location is chosen, the vote for it would likely occur in April. But the site across the river sits in Clay County, and that would potentially require a different funding structure than what has long been envisioned.

Another factor is that the Royals have shared that tax revenue with the Chiefs, because Kauffman Stadium shares the Truman Sports Complex with Arrowhead Stadium. But the NFL franchise prefers Arrowhead Stadium rather than build anew, and how those two franchises can continue to co-exist in different locations is not entirely clear.

Regardless of the choice of location, Sherman has said the new Royals stadium will take about three years to complete, which would mean opening day for the 2027 or 2028 season. He also said in a recent letter to fans that the project would create about 20,000 jobs, produce roughly $1.4 billion in labor income and $2.8 billion in total economic output, while its inaugural season would "generate some $185 million more in regional economic output than The K does today."

Much of that money would come from premier seating and club spaces that are not possible at Kauffman Stadium, which has long been one of the jewels of Major League Baseball, but is currently the fourth-oldest park still in operation.

"Our region is at a critical juncture, and I say that in a positive way," Sherman said. "We have a new airport. The World Cup is coming (in 2026). We just hosted the NFL Draft. We have a women's soccer stadium coming out of the ground on the riverfront, the only one of its kind, and the Chiefs and Royals are talking about doing some really special things for this community."

Manfred pointed to the way new stadiums for the Nationals and Braves have driven revitalization and revenue.

In the case of the Nationals, their new ballpark has sped up development of what was once a largely industrial neighborhood known as Navy Yard in Washington, D.C. In the case of the Braves, the glittering new Truist Park serves as the fulcrum of The Battery Atlanta, where restaurants and high-end residential areas have sprung from the ground.

"I lived in the District, worked in the District for 15 years. The Navy Yard, where Nationals Park sits, the time I lived there you wouldn't go there. Nobody went there," Manfred said. "If you go there now, you have the ballpark, all this development, high-class housing, mixed-use development. ... (In Atlanta), they built a city where there was none. It has become one of the prime entertainment centers in the metropolitan area where there was nothing."

Both of the Kansas City sites are optimal for development in that they are riddled with old, vacant buildings and empty lots. But both also would require substantial investment in parking, ingress and egress, and other infrastructure.

"This process that we're in the middle of right now - evaluating - it's imperative we do this right now to find a new home, a new stadium, a new ballpark," Sherman said, "but as importantly a new location where we can bring vibrancy and energy around the ballpark and do great things for this city."