Prince William County’s minor league baseball team is getting closer to a deal to bring a new ballpark to Woodbridge, its owner told the Board of County Supervisors recently.

Potomac Nationals’ owner Art Silber also said the stadium’s financing and other details must be finalized next year for the team to stay in Prince William.

In July, Silber and state and local officials announced a deal for a $25 million, 6,000-seat ballpark as part of Stonebridge at Potomac Town Center. The proposal would expand Stonebridge, which is anchored by a Wegmans grocery store. Officials hope the $70 million public-private partnership will serve as a commuter hub and major retail and housing development just off Interstate 95.

The Class A team became affiliated with the Washington Nationals when the major league franchise moved to the District in 2005. The team has long played at G. Richard Pfitzner Stadium, a county-owned facility behind the central county office building in Woodbridge. Pfitzner Stadium has been beset by maintenance problems in recent years and been a source of friction between Nationals officials and the Potomac Nationals.

The team has been looking for another ballpark since the 1990s, and leaders hope the plan announced in July would provide it with a permanent home.

Silber told supervisors Nov. 19 that approvals must be in place for the team to begin construction on the ballpark by 2015. If that doesn’t happen, the team might move elsewhere, per its agreement with Major League Baseball officials to find a more suitable site.

“If this did not happen, there could be a real question as to the future of the club continuing in Prince William County,” Silber said.

Still, he said, the team is “pretty darn close” to a major naming-rights contract for the stadium for its financing, he said.

In his presentation to the board, Silber outlined plans that model a new stadium on the District’s old Griffith Stadium, the primary sports complex for football and baseball in Washington until the 1960s.

Supervisors told Silber that they were looking forward to the new stadium coming to fruition. The plan would still face scrutiny by the county Planning Commission and supervisors. Not all residents support the stadium, which would bring traffic to the area.

At a meeting in October, Selena Burroughs of Woodbridge said that the county has plenty of extracurricular activities and that it should be focused on high-paying jobs.

“A stadium’s nice, but is it needed?” Burroughs asked.

Parts of the deal have been tentatively hammered out. The Commonwealth Transportation Board has authorized the Virginia Department of Transportation to invest about $15 million for a parking structure, with about 1,000 spaces for fans and commuters catching rides on I-95.

Roadside Development, which manages Stonebridge, would invest about $30 million in site and infrastructure work. And the team would pay for construction of the stadium.