Rory McIlroy admits the fear of regret fuelled his change of heart over competing at the Olympics.

The Northern Irishman is on home soil for this week's 148th Open Championship, having caused a stir with comments he made at the same major three years ago.

At Royal Troon, ahead of the 2016 Olympics in Rio, McIlroy suggested he would not even bother to watch the golf competition, which ended up being won by Ryder Cup team-mate Justin Rose.

Despite his dismissive tone then, McIlroy - who initially cited the Zika virus as the reason for his absence from Brazil - had clearly shifted his stance when he addressed the issue at Royal Portrush on Wednesday as he now has Tokyo 2020 firmly in his sights.

"I think personally I needed to do a lot of inner thought and ask, 'Is this important to me? Why do I want to play it? Who do I want to represent?' All that sort of stuff," he said, with his decision apparently complicated by whether he would turn out for Ireland or Great Britain.

"At the start whenever I was thinking of playing the Olympics, I think I let other people's opinions of me weigh on that decision. And at the end of the day, it's my decision. I can't please everyone. 

"The only people that really care about who I play for, who I represent, don't mean anything to me. I don't care about them.

"So at the end of the day, I think with where golf is, with it being part of the Olympic movement, I think if I had to look back on my career and not played in one, I probably would have regretted it. 

"So that was part of the reason I wanted to go, for the experience, as well. It's going to be - it's a wonderful experience. I've never done anything like that before.

"And it's in Japan. I enjoy Japan. I enjoy the people. I enjoy the food. So it will be a nice week."

The 30-year-old is going in search of a second Claret Jug and fifth major, having not won one of golf's four landmark events since 2014.