Details are trickling out about the papal trip to America this spring — and the Washington Post has some intriguing behind-the-scenes nuggets about his visit to the nation’s capital:

Which position will the pope take up at Nationals Park? Second base or center field?

Curious questions face organizers preparing for the arrival of Pope Benedict XVI, whose three-day visit to Washington in mid-April will allow few opportunities for the public to see him.

From the White House to Catholic University to the new ballpark, the first papal visit to the District in 29 years will be tightly controlled and highly security-conscious. There will be no motorcades through the streets, with the pope standing and waving in a convertible, as Pope John Paul II did when he visited in 1979.

“Post-9/11 security concerns have changed that,” said Susan Gibbs, spokeswoman for the Archdiocese of Washington, which is organizing the only public event here on Pope Benedict’s schedule: a Mass at the stadium at 10 a.m. April 17.

Hence, the debate over where on the field the pope will celebrate Mass.

With requests for thousands of tickets pouring into the offices of the archdiocese, officials are looking to squeeze as many people as possible into the stadium.

At first, the decision was made to put the altar at second base, which is where Yankee Stadium officials place the altar for papal Masses, Nationals and archdiocese officials said.

But after looking at plans for Nationals Park, which is under construction, organizers realized that they could fit in 4,000 more seats — for a total of 45,000 — if they placed the altar at center field, said Heather Westrom, the Nationals’ director of ballpark enterprises.

And so, the pope will celebrate Mass from deep center field.

The doors will open about 6:30 a.m. for pre-Mass activities, including music and videos. During the two-hour Mass, local Catholics will play a big role. Seminarians will be altar servers, and laypeople will be chosen to read Scripture. Music will be provided by Washington area parish choirs.

Plans for distributing tickets have not been completed. In the past, tickets to major Catholic events have been distributed through parishes and Catholic organizations.

The archdiocese has been asked whether non-Catholics can attend (yes) and whether the Mass is part of the Nationals baseball ticket package (no).

The archdiocese is trying to keep the free tickets from popping up on eBay and falling into the hands of scalpers.

The Mass “is for the faithful who want to be with the Holy Father,” Gibbs said. “It shouldn’t be an opportunity for people to make money.”