Open 2014: Rory McIlroy's mixed form 'getting into his head'

McIlroy has two majors to his name but won the last in 2012

Rory McIlroy admits his failure to back up a low first-round score with a solid second is "getting into his head" as he prepares for this week's Open.

Last week, he shot a course-record 64 on day one of the Scottish Open only to follow it up with a 78.

"I have no problem shooting a low one on Thursdays, so there should be no reason I have any problem shooting a low one on Fridays," he said.

"I need to go out and pretend like it's a Thursday again."

McIlroy also carded a 63 and a 78 at the Memorial earlier this season and suffered a seven-shot swing in another US Tour event.

"I'm putting pressure on myself to back up a low round on Thursday," said the 25-year-old Northern Irishman.

"I just need to try to keep it a little tighter when things aren't 100%."

McIlroy said he felt "unconscious" and "brain dead" after carding an eight-over-par 79 on day one of the Open last year.

He will tee off in the 2014 event in the same group as Japan's Hideki Matsuyama and USA's Jordan Spieth.

The former world number one won the last of his two majors in 2012 and has struggled to add to that tally.

He goes into the Open having ended his engagement to tennis player Caroline Wozniacki in May.

Following the split, he won the PGA Championship at Wentworth but then missed the cut at the Irish Open.

"It just seems I've been caught out this year by a bad stretch of holes every tournament," said McIlroy.