Tennis-Schedule of Monday's featured matches at U.S. Open

NEW YORK, Aug 27 (Reuters) - Schedule of featured matches on the opening day of the U.S. Open tennis championships on Monday (prefix denotes seeding): Arthur Ashe Stadium (Starting 1500 GMT/11 AM ET) 7-Roberta Vinci (Italy) v Anna-Lena Friedsam (Germany) Polona Hercog (Slovenia) v 2-Angelique Kerber (Germany) 4-Rafa Nadal (Spain) v Denis Istomin (Uzbekhistan) (starting 2300 GMT/7 PM ET) 1-Novak Djokovic (Serbia) v Jerzy Janowicz (Poland) 8-Madison Keys (U.S.) v Alison Riske (U.S.) -- Louis Armstrong Stadium (Starting 1500 GMT/11 AM ET) Rogerio Dutra Silva (Brazil) v 7-Marin Cilic (Croatia) Francesca Schiavone (Italy) v 9-Svetlana Kuznetsova (Russia) Elise Mertens (Belgium) v 3-Garbine Muguruza (Spain) (not before 2130 GMT/5:30 PM ET) 26-Jack Sock (U.S.) v Taylor Fritz (U.S.) -- Grandstand (Starting 1500 GMT/11 AM ET) Taylor Townsend (U.S.) v Caroline Wozniacki (Denmark) (not before 1700 GMT/1 PM ET 20-John Isner (U.S.) v (U.S.) 9-Jo-Wilfried Tsonga (France) v Guido Andreozzi (Argentina) 13-Johanna Konta (Britain) v Bethanie Mattek-Sands (U.S.) (Reporting by Larry Fine; Editing by Andrew Both)