Rory McIlroy: 'Yes, I have changed. It is all part of growing up'

The Ulsterman says splitting with his agent Chubby was toughest decision of his life but it was strictly business.

Golfer changes agent. So what? It should be right up there with "man changes bank", or "rock star changes dealer". Except the golfer happens to be Rory McIlroy, thus it is perceived to mean an awful lot. Here yesterday, the young Ulsterman with the world at his feet and the world at his letterbox explained how this realisation has hit him since he split with Chubby Chandler two weeks ago.

However perverse, however absurd, this was a confessional box he just had to enter. Granted, he did not spill his soul. And many did depart the huddle at the Shenshan International Golf Club with something greater than a mere submission that it had been "only a business decision, nothing personal" which caused a 22-year-old, after the year of his career, to leave the management company which has guided him since he turned pro, and yes before. But he faced up and answered the questions. At the same time as looking utterly mystified by all the fuss.

"I was surprised at how much of a big deal was made out of it, because these things happen out here all the time," said the US Open champion, after his final practice round for the HSBC WGC Champions. "It just seems that with me it's made a bigger deal. It's not that big a decision."

Of course, it was "big" in terms of what it meant to McIlroy and, even more so, what it meant to Chandler and a group overseeing the likes of Lee Westwood and three major winners. If McIlroy has the type of success all but the contrarians in the trade forecast, it will probably run into many tens of millions "big" for the Cheshire agency. No, McIlroy knew the scale of it on that score.

"It was probably the hardest decision I've ever had to make in my life," said McIlroy, who was first introduced to Chandler by Clarke when he was barely out of his first spikes. "And it's the toughest conversation to sit down with the person who has been there for you for the past 10 years. Look, I'll never forget what Chubby and ISM have done for me. They're a huge part of my career and if it wasn't for their help I wouldn't be in this position."

It was the timing which caused the biggest ripples in a sport which likes to coexist in a mill pond. McIlroy has just enjoyed his first major, and with the stock of Tiger Woods still in the sort of free fall most brokers would balk at, the noughts on his portfolio were lining up. And when he informed Chandler in an airport lounge in Bermuda, he had just spent two weeks in his company on a seven-day, seven-city exhibition in China and then four days at the Grand Slam of Golf. Chandler, a larger-than-life figure who prides himself on having his finger, if not his entire grip on the pulse, understandably felt like he had been left at the altar. However, McIlroy maintained this was not a fit of pique.

"It's not a decision I made overnight," he said. "I thought long and hard about it and I spoke to my Mum and Dad, who are 100 per cent behind any decision that I make. It really wasn't personal; it was just business."

In the aftermath, Chandler indicated that he, too, thought the reason was primarily business – essentially that McIlroy wasn't pleased with his "brand", nor with the stature of some of his sponsors. There was even the notion put forward that his burgeoning relationship with Caroline Wozniacki, the world No 1 tennis player, had turned his head to the potential of such fame. McIlroy dismissed all that with something resembling a harrumph.

"I felt like, for four years, Chubby was the best person and ISM were fantastic for me," he said. "But sometimes to progress you need to have a fresh view on things. And this was something I felt I needed. It's not about endorsements or anything like that. It's about me trying to play my best golf. And that's all there is to it. And I feel that a new environment around me would enable me to do that. I can't put a date on when I decided. I'm not saying that it has been in my mind for a few years, but I have always seen at close hand how great a job Conor [Ridge] and [McIlroy's new agency] Horizon have done for G-Mac [Graeme McDowell]. That's something that has always been in front of me."

McIlroy is not denying he has changed. But he fails to see why the cynics believe that all the success has altered him for the worse. "Of course I've changed," he said. "It's all part of growing up. I'm still only 22 – there are people my age who are still at university. I've had a lot of life experiences over the past few years. I feel like the [Unicef] trip to Haiti changed me; I feel like winning the US Open changed me. So there have been a lot of things this year that have maybe not only changed me as a person, but also changed my view on things."

The young Tiger comparison is as obvious as it is inevitable. He, too, switched managers as the spotlight intensified and he, too, was forced to accept that every minute detail of his life would be placed under the microscope. Perhaps McIlroy hasn't yet reached those levels; perhaps he never will. But it has got to the stage where he can nod at a journalist who referred to him as "the new Tiger".

"Yeah, I've been shocked at my profile," he said. "The things that go on... well, to my mind, like I said it doesn't seem like a big deal. I don't know whether it's just me. I've said a few things this year that I probably should not have. For instance, after the Open when talking about the bad weather and how I wasn't going to change my game. Some things you say in the heat of the moment, that if you actually thought about a bit, you wouldn't say. Apart from that, I just try to be honest. I always want to be that way, I don't want to be guarded and give meaningless answers. I still want to be myself."

Himself now is quite something to behold. Last night at an HSBC function he joined Wozniacki on a simulated tennis court which measured their speed of serve. This is the only time in McIlroy's life where he will be laughed at for shooting 59 against someone who scored more than 100. The mph clock made for hilarious viewing.

Yet this morning he resumed his day job, not as one half of sport's famous couple, not even as the heir to the Tiger circus. But as the boy from Belfast who has his eyes on another title. Last week he won £1.25m at the Shanghai Masters and now he attempts to win just his fifth title at this World Golf Championship extravaganza. The near £750,000 first prize would leave him £400,000 short of world No 1 Luke Donald in the European Tour Order of Merit. "I'm a long way behind Luke, but I have a chance here to cut into his lead," he said. "That's all I'm concentrating on." If only it was so simple.