Legendary tennis coach Rick Macci admitted he wasn’t impressed at first by Serena and Venus Williams but it didn’t take him long to completely change his mind. Macci was one of the first coaches to work with the Wiliams sisters and he was amazed by the level of talent they had. “I wasn’t impressed at first. But then when they started competing, it was brutal,” Macci said during his interview with YouTube channel Tweener Head, as quoted on Sportskeeda. “I’ve seen a lot, I never saw two little girls run so hard and almost fall over to get a ball.Quick, strong, fast. And they would go for the jugular.” The Williams sisters went on to become all-time greats and Macci wasn’t surprised at all. “I knew they could transce …