McIlroy tees off at the seventh at Augusta during a practice round for the Masters
Tom Watson has backed Rory McIlroy to complete the career grand slam which eluded him as the 66-year-old prepared to make his final appearance in the Masters.
Watson won a total of nine major championships during his illustrious career, including the Masters twice and five Open titles, but never won the US PGA Championship in 33 attempts.
McIlroy's first attempt to join Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods in winning all four major titles ended in disappointment with a fourth-place finish at Augusta National last year.
But former Ryder Cup captain Watson believes the Northern Irishman is capable of "emasculating" any golf course and has the ideal game to succeed in the predicted tougher conditions this week.
"He's the guy. He's my pick this week," Watson said. "He's just got a tremendous talent. He hits the ball high. I think it's always been an advantage to hit the ball high on this golf course.
"And I can tell you the golf course is different this year than it was last year. The greens are faster yesterday and today than they were last year. They sped them up. They seem just a little bit harder.
"Today (Tuesday) they had a real sheen to them. Number five was like a mirror. They are out there syringing the greens, so I think you're seeing a little bit different set-up this year. I think it's going to be a tougher set-up. And the people that hit the ball high, they have an advantage.
"Rory, he can emasculate a golf course, he flat (out) can. He hits the ball high and so far."
Not being able to hit the ball too far these days is the reason Watson has decided to call time on his competitive career at the Masters, although he will continue to play in the par-three contest and on the Champions Tour.
"I made the decision last year to announce at the Open Championship that this was going to be my last Masters," added Watson, who has not made the cut at Augusta since 2010.
"In my toolbox I have one of those tape measures and that tape measure used to extend out to 265 yards carry off the tee. And now it doesn't do that any more. It's 250 yards off the tee.
"When you see these kids play out here and see them carry the ball 280 and 290 yards off the tee, it's time to say I can't compete with them. And I haven't been able to really honestly compete with them for several years."
Asked what his legacy in golf would be, Watson added: "You have to ask other people that. I just hope that when all is said and done that my peers say that Watson was a hell of a golfer.
"I just want to be remembered by my peers, the guys that know what it takes to be a championship golfer. I hope that also going throughout my career, that I've treated people the way they should be treated. Sometimes I haven't. But most of the time I have, I think, and I think that's important."