Andrea Petkovic tells Tennis Grandstand that the most embarrassing moment of her career was at the 2010 U.S. Open when she met up with John McEnroe prior her fourth-round match against Vera Zvonareva.

“Before my warm-up McEnroe came to me and he was like, 'Good luck, Petko.' I was so nervous,” she recalled. “He said to me, 'I’m going to be commentating on your match.' I was so nervous that I lost 6-1, 6-2. I didn’t put in one ball! I was just thinking about John McEnroe during the entire time of the match!"