With their proposed site for a baseball stadium on the doorstep of affluent Fairfax County, its spending power and million-plus residents, boosters of a Northern Virginia team would welcome a little cheerleading from the leaders of Washington's largest suburb.

But for the time being, county supervisors are mum on baseball. Elected leaders in neighboring Loudoun have been buzzing for weeks about hosting a ballpark near Dulles International Airport, invoking regional pride in a suburban location they hope will beat out the District and several other potential sites as the new home of the Montreal Expos. But Fairfax supervisors say they have no immediate plans to discuss, endorse or otherwise weigh in on the plan.

"Whether baseball goes to Loudoun County is undoubtedly an important subject," Board of Supervisors Chairman Gerald E. Connolly (D) said. "It's just not a tier-one subject."

He cited "many more pressing things" on the board's radar, including a major effort to thwart a growing gang presence.

Supervisor Linda Q. Smyth (D), whose Providence District straddles the Capital Beltway, echoed the chairman's nonchalance, taking a micro-view of the national pastime.

"Baseball has not been at the top of my list," Smyth said. " I know it's been bouncing around from Arlington to Dulles, but every time it bounces, it skips over Providence."

The Washington Post took an informal poll of some Fairfax supervisors after members of the Montgomery County Council, their Maryland counterparts across the Potomac, threw symbolic support this month behind returning a team to the District. Council members criticized Northern Virginia boosters for overblowing the benefits of the Loudoun site, which would rise in the center of a mixed-use development of thousands of condominiums and single-family homes and 5 million square feet of commercial space.

The Fairfax County Chamber of Commerce endorsed the Loudoun project, dubbed Diamond Lake, last week, citing the economic benefit of a potential spillover of new jobs across the county line.

Some supervisors, however, express skepticism that Major League Baseball actually intends to bring a team to the Washington region at all, having discussed it for years.

Then there is also the issue of thousands of cars spilling over into Fairfax's clogged road system.

The board voted in 2003 against locating a team at a proposed stadium site at Fort Belvoir's former Engineer Proving Ground in Springfield.

Supervisor T. Dana Kauffman (D-Lee), who is on record opposing a Northern Virginia stadium, said the influx of cars would overwhelm an already dysfunctional grid whose state funding was just cut by 24 percent.

On the other hand, the stadium, which would be near a proposed Metro stop east of the airport, could prove to be a catalyst for a project backed heavily by the Fairfax board: a rail extension to Dulles. The long-planned project is now limited to 11 miles ending in Reston, but Virginia leaders hope to take it the 23 miles from West Falls Church to the Dulles area.

Loudoun board Chairman Scott K. York (I) is not scheduled to brief that county's supervisors on the stadium plan until September.

Meanwhile, the Virginia Baseball Stadium Authority has offered to brief board members individually, said Brian Hannigan, a spokesman for the group.

"We would certainly like for them to be supportive," Hannigan said. He called a Loudoun ballpark "a terrific benefit for Fairfax County" that would "improve the quality of life for hundreds of thousands of residents."

Connolly said he wants to see more data. "Until we see details about the impact" of a Loudoun stadium, "people on the board are keeping their powder dry." Sales tax revenue generated by a stadium would go to Loudoun, he said, but he noted that service jobs to support concessions and other ballpark-related business could originate in Fairfax.

The one certainty is that bringing baseball to Northern Virginia arouses passions on both sides. This could explain the silence of a county whose leaders love to preach regional thinking.

Or, as Supervisor Michael R. Frey (R-Sully), who also serves as the stadium authority's vice president, put it, there's always the cloak of zoning law. Did Fairfax weigh in when the Prince William supervisors approved construction of Potomac Mills mall, which opened in 1985. Or when they considered Disney's controversial plan eight years later to build a theme park near the Manassas Battlefield?

Said Frey: "I say, it's dangerous to stick your nose in other people's land-use cases."