The negotiations that led to Pope Benedict XVI’s scheduled appearance in the Washington Nationals’ ballpark in April began with a personal call from Washington’s archbishop to the Lerner organization that owns the team, said a person close to those talks.

That initial call from Archbishop of Washington Donald Wuerl has touched off energetic planning that is still well short of completion, said Mark Touhey, a former chairman of the D.C. sports and entertainment commission who has been informally involved in the talks.