EXCLUSIVE: "Serena can come back and not only win Grand Slam, she could be no. 1" says former coach Macci

"If she wants to do it, she has to fully commit and get in amazing shape. You don't lose the talent, you just lose the fitness. Then you get the confidence back once you start playing matches."

"She just has to dive in get used to winning and losing. She's probably the best competitor maybe in any women's sport we've ever seen."

"Serena is like a pit bull. When she gets a hold of you, she doesn't let go. She's a brutal competitor, and she has that serve. She can hit fifteen aces a match still."

"If she wants to do this and really go after it, I have no doubt that she can do it because you never underestimate a heart of a champion."

"This young lady was wired differently at ten years old when I saw her. Just the way she's put together. I know she has other priorities in her life, she's a mother now. But if she wants to do this, one hundred percent, she can come back."

"And I think she could not only win Grand Slam, she could be number one if she wanted to but that's a question only she can answer."