The world's best golfers will gather next week in Augusta, Georgia, for the Masters Tournament, arguably the crown jewel of golf's four majors. Among this year's field is defending champion Jordan Spieth, who tees off Thursday in the Shell Houston open - the final tournament before golf's majors season gets underway.

Spieth lost his number one ranking this week, but still hopes to keep the coveted green jacket, reports "CBS This Morning" co-host Charlie Rose.

Even with his eyes closed, his swing is spot on.

Last year at the age of 21, Spieth became the second youngest man to win the Masters, his favorite tournament in the world.

"You know, I came close in my first attempt in 2014. And then last year, got off to just a hot start. We were able to hold it together. It was really, really incredible," Spieth told Rose at the New York's Golf Club at Chelsea Piers. "There, you're playing the golf course. And this year's going to be tricky because last year, we were 18 under. And the hardest thing to do in repeating -- or trying to repeat -- a win is to not look at the year before and think that it's just going to be like that."

It's hard to believe he was nearly on a path to play baseball, like his father Shawn. Spieth said it was "100 percent" the right decision, but one of the hardest things he's had to do was to tell his father he was going to play golf.

"I remember exactly where I was when I told him. I mean, I must have been 12 or 13 years old and I said, 'Dad, I really just want to specialize in golf now and play a little bit of basketball."

Family remains Spieth's top priority. His younger sister Ellie -- who was born with a neurological disorder - is his greatest fan.

"We have a unique family and a unique position. Having a special-needs sister kind of changes your life, every person in our family. It changes the sacrifices my parents have to make. And then for us, it's so special," Spieth said. "It's so special to see her development. It's so special to see how she can continue to conquer struggles that we take for granted."

Spieth slipped from his number one world ranking last week when he lost the Dell Match Play championship.

"And that was a really tough loss. And it proved to me that no matter how many times you get yourself into position, whether it's a major or regular tournament, there are going to be some breaks that go your way and sometimes, they're just not going to," Spieth said. "That's why it's so difficult to win."

Before Jordan Spieth, there was Tiger Woods. Though no longer a major threat on the course, he remains a central figure to the sport and an inspiration to Spieth.

"He made it cool. He made it athletic. He showed that he kind of had an influence on a younger generation of athletes that maybe [thought], 'Hey, golf's cool. Let's try golf,'" Spieth said. "And you know, it certainly was that way with me."

Spieth is one of the many young golfers in the game today influenced by Woods, who are now crowding an already competitive field. But he said he'd be "shocked" if somebody won the Grand Slam, especially up against the older players.

"Look, I mean Phil Mickelson is contending to win events still and he's in his mid-forties. Then you have these guys that are around- their mid-thirties -- Adam Scott, Sergio Garcia -- these guys that have been around since they were teenagers who are still in their prime. And then there's the 20-something-year-olds," Spieth said. "Rory McIlroy is still more accomplished than anybody else. He and Phil (Mickelson) are the most accomplished players that are playing on the PGA tour right now."