TENNIS’ LATEST VOLLEY: The U.S. Open has found a new playing field and it’s not in Flushing Meadows. Instead, the tournament on Friday opened a pop-up shop at 129 Prince Street in New York City’s SoHo neighborhood. The store, which is on the corner of Wooster Street, will be open from 10 a.m. to 7 p.m., seven days a week, through Sept. 10. It will offer U.S. Open branded apparel officially licensed by the U.S. Tennis Association. In addition, there will be a vintage Tad Davis clothing line that captures the spirit of the 40th anniversary of the Open era, cobranded by Under Armour. A limited edition 100 percent organic cotton U.S. Open T-shirt designed by Heidi Klum also will be available. Klum’s design features butterflies drawn with her children’s crayons, where the body of each butterfly is a tennis ball. The 2008 U.S. Open, which started Monday, is being held at the USTA Billie Jean King National Tennis Center in Flushing, N.Y., through Sept. 7.