Rory McIlroy maintains he is not just using his debut at the RBC Canadian Open as preparation for an assault on the US Open title at Pebble Beach.

The 30-year-old Northern Irishman heads to Hamilton looking to build momentum into the third major of the year and on the back of a disappointing performance at the Memorial Tournament.

Having missed the cut in each of the past three US Open events, McIlroy believes delivering a strong showing through all four rounds in Ontario will be crucial.

"This isn't just a preparation week. This is a very prestigious tournament, one of the oldest tournaments in the world that I would dearly love to be able to add my name to," said McIlroy, who claimed his first major triumph with victory in the 2011 US Open at Congressional.

"I've heard a lot of great things about Hamilton and I'm excited to be here.

"It's a very strategic golf course. You've got to put it in play off the tee, and I'm definitely going to have to drive it better this week than I did last week.

"There's a variety of different tee shots that you need to hit, with different clubs, and the greens are going to be a very similar type of grass.

"The rough is pretty thick as well, so if you miss it in the rough you're doing well to get it up by the green. And then, if you do miss greens, it's going to be pretty similar in terms of the lies that you get.

McIlroy told reporters at a press conference: "I'm fully focused on this week, but knowing that if I play well here this week, and have good control of my ball and my distance control, that that will serve me well going into next week."

Defending champion Dustin Johnson will be another looking to make an impact through this weekend.

The American world number two, though, is no longer working directly with long-time coach Claude Harmon III in a new set-up moving forward.

"I've always worked with coach (Allen) Terrell, I've always worked with Butch (Harmon) and Claude, so it's not really a change," Johnson said.

Johnson played the last four Canadian Opens contested at Glen Abbey Golf Club but is ready for the challenge of tackling the shorter Hamilton course, the players having been taken off for spells during Wednesday's practice round because of rain and dangerous weather conditions.

"It's kind of an old school golf course. Got to hit it straight, but I like it so far, what I've seen," said Johnson, who finished runner-up at the PGA Championship last month.

"I feel like I'm rested. I'm mentally sharp, and I'm ready to go for the last push through the end of the year.

"I've got a lot of really big tournaments coming up, and for me, it's just about putting myself into position to have a chance to win."