Coach Rick Macci on Sharapova: "She had that mental box at 11 already, I didn't see it in Williams"

Having worked with both Maria Sharapova and Serena Williams during their youth, legendary coach Rick Macci believes the Russian surpassed the American in mental strength at an early age.

Macci has worked with hundreds of tennis players at the start of their careers, with several turning out to be all-time greats. The 68-year old recently compared Sharapova to Williams, stating while the latter was the more athletically talented at a younger age, Sharapova's mental prowess was more impressive.

"You’ve got to remember to forget," said Macci in an interview with the ATP Tennis Radio Podcast. "You got to have the ability to forget. In tennis, it’s very tricky and this separates great from good. You know great is rare air. There’s a lot of good athletes, amazing athletes on the WTA and ATP tour but they’re not the leaders of the clubhouse.

"They didn’t become a [Rafael] Nadal… I know it’s a package – the forehand, backhand, serve – you have got to check a lot of boxes. Serena checked every box and created a few more but you have got to check every box.

"But the mental part -- how you handle pressure… and the ability to forget. You have got 20 seconds to flip it in your mind like it happened 20 years ago. That’s why I love Sharapova… even at 11, she was in a bubble. I called it. Even though she was limited athletically, she had that mental box already there. It was amazing. I didn’t see it in Serena."