CARNOUSTIE, Scotland (REUTERS) - Rory McIlroy has promised to "go down swinging" at Carnoustie after a second straight two-under-par 69 at the British Open on Friday (July 20).

The Northern Irishman thinks he was too tentative in the first two majors of the year, and promised to make sure it does not happen again.

The four-times major champion endured a disappointing Sunday at the Masters, where he finished equal fifth after starting the final round in second place, and also hit a miserable opening round 80 at the US Open that led to a missed cut.

"Sunday at Augusta was a big learning curve because even if I hadn't won but I went down swinging and aggressive and committing to every shot, I would have walked away a lot happier," said McIlroy, who trails clubhouse leader Zach Johnson by two strokes at Carnoustie.

"So I'm committing to making sure, even if I don't play my best golf and don't shoot the scores I want, I'm going to go down swinging and giving it my best.

"Focusing on the results too much... not focusing on the process, I've sometimes forgotten that and just need to get back in that mindset.

"One of my main thoughts is just to let it go, just go out there and give it your all and I'd rather fail by trying 100 per cent than by holding back and not giving myself the opportunity to do well."

Giving it your all does not mean playing with wild abandon, however.

The Northern Irishman was cautious at times off the tee on Friday, as some light morning rain took the fire out of the previously bone-dry links.

He used his driver only six times, adjusting his strategy to the conditions on a day when the ball was not flying as far through the air.

"The game play that I was trying to adapt to be aggressive and hit driver a lot, I just couldn't do it," he said.

"All the bunkers were in play (hitting driver) and then with it being wet, spin rate goes down and it could go either way, so I hit a lot more irons off tees and was a lot more conservative."

McIlroy, without a major win since the 2014 PGA Championship, does not envisage a round in the low 60s over the weekend, but believes the mid 60s is feasible.

"I don't see a ridiculously low score out there, but I definitely see something like what Tommy shot today, a 66 or 65, I think I'm capable of that."

Tommy Fleetwood carded 65 on Friday.