Rory McIlroy is back at the tournament that "kick-started" his amazing run over the past 12 months.

McIlroy defends his title this week at the BMW PGA Championship at Wentworth, the flagship event of the European Tour. He won here in 2014 after failing to make the cut the previous two years.

"This is what kick-started everything," McIlroy said Wednesday. "This win, it gave me a lot of confidence to go on into the summer and do what I did. It was a real catalyst."

He has won seven events in the last 12 months, including two majors — the British Open and the U.S. PGA Championship — and established himself firmly at the top of the world rankings.

On the eve of last year's event, McIlroy appeared to fight back tears as he faced the media to detail the split from his fiancee, Danish tennis player Caroline Wozniacki, which had been announced in a statement a few hours earlier.

McIlroy managed to put aside the distractions and finished the tournament with a 6-under 66 to beat Shane Lowry by a stroke.

"I felt like I was playing well before but I was not able to turn good finishes into wins," he said. "Who knows, if I didn't have this tournament, a few things might have been a little bit different. This is a tournament I wasn't sure I would ever win in my career just because of my relationship with the course."

The Northern Irishman stopped short of saying he intimidates his opponents but believes his stature in the game has never been higher.

"I feel like my name now carries a certain weight on a leaderboard," McIlroy said. 'I don't know if that is intimidation but I just feel that players see my name on the leaderboard now and it might mean a little bit more than it used to."

As well as his doubling his number of major victories last year, McIlroy also won the WGC Bridgestone Invitational, the Dubai Desert Classic, the WGC Match Play in San Francisco and the Wells Fargo Championship at Quail Hollow last week.

Now a four-time major winner, McIlroy said he felt "a little bit of jet lag" after flying straight from his record-setting seven-shot victory at Quail Hollow to London, but believes the adrenaline of teeing off on Thursday alongside U.S. Open champion Martin Kaymer and Jamie Donaldson will kick in.

"I feel OK. I will just try and rest up again tonight and make sure I am feeling fresh and ready to go tomorrow," McIlroy said. "Once I step on the first tee tomorrow and get a card in my hand it'll be different."

Justin Rose spoke of his desire to derail McIlroy's defense and win a tournament that he grew up attending as a youngster.

"Obviously growing up so close to here, this tournament is even more special to me than it should be," Rose said. "This would be very special for me to add this one. Call it a bucket-list tournament. Outside of the major championships, I can't think of a tournament I would like to win more."

Patrick Reed, who announced his withdrawal from Wentworth and next week's Irish Open on Tuesday, told the Golf Channel he decided to stay in the United States because a family member is terminally ill.