Rory McIlroy has attempted to remain optimistic about his chances in Aberdeen after wasting a lead at the Scottish Open on Friday.

The Northern Irishman started day two with a one-shot lead thanks to a course-record 64 on Thursday, but his second-round troubles surfaced again as he carded a 78 to fall back to level par, and he admits that he was not expecting such a difficult day.

"It's been the case all year. I've got off to great starts and fell away but I am still in the tournament and I can go out in the morning and try to get some of those shots back," the 25-year-old told reporters.

"I just thought everything today was much tougher. When I woke up this morning and went to the gym the wind didn't seem like it was up as much as it is now, so I wasn't expecting this tough a test."

Ricardo Gonzalez, Marc Warren and Kristoffer Broberg hold a one-shot lead at the halfway stage of the event.