I'm one injury away from hanging up the racket at any time.

I think I was as mentally tough as I've ever been. I felt like I handled the situation both on and off the court extremely well. I felt like I needed to.

I feel like when I'm match tough and match hard and played a lot of matches I got that competitive winning spirit going and I can get on some rolls like I did last year. I won San Jose, Indian Wells and made the semifinals in Miami so it can happen for me.

I'm one injury away from hanging up the racket at any time.

Even when I was No. 1 in the world, I was taking it one match at a time. I never was a player to look too far ahead, the way draws can pan out.

I was lucky enough to win the Davis Cup in my first year in 1999. I won my first slam at the U.S. Open in 2001 and became world No. 1 later that year. By the age of 20, I'd done it all.

I've probably put up with more criticism than a lot of people out there. At the end of the day, you block out everything, especially with your personal life.