Rory McIlroy refused to blame the pressure of chasing a career grand slam for a disappointing performance in the 83rd Masters.McIlroy needs a victory at Augusta National to join Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods in having won all four major championships.But, while a 43-year-old Woods was doing battle for a fifth green jacket at the top of a star-studded leaderboard in the third round, McIlroy was putting the finishing touches to a second consecutive 71 to finish one under par.“It was just one of those weeks, just not quite had it,” McIlroy said after an erratic round containing an eagle, four birdies and five bogeys.“I have not read anything. I knew my game was good coming in here, I’ve not let any external pressure get to me. I know I can play this golf course, just this week I have not played it well enough.”

A rain-softened course was expected to play into McIlroy’s hands, but the 29-year-old added: “I don’t think this course plays easier when it’s soft.

“You get mud balls – I got a couple of flyers off the fairway – and when your iron play has to be its most precise of the year, to have mud balls is really tricky.

“I’ve just been making too many mistakes. I’ve been making the birdies and doing the things that you need to do around here. If I’ve missed a green I haven’t got it up and down or put myself out of position.

“The rough this year is about a quarter or half an inch longer than it usually is, and it’s just hard to get control of your ball out of it. And I just haven’t driven it in the fairway enough to have control going into these greens.

“I’m under par for the tournament, I’m just not enough under par.”