Rory McIlroy admitted he was shell-shocked after another frightful Friday in which he shot 78 meant he tumbled down the leaderboard in the Scottish Open.

McIlroy had led overnight, but carded six bogeys and a double-bogey in a second round that left him uncomfortably close to the cut, a remarkable fall from grace following his course-record opening round of 64 on Thursday.

His 78 meant that he finished the day on level par, some way behind the early clubhouse leaders Sweden's Kristoffer Broberg and Scotland's Marc Warren, both of whom ended the day on six under par.

"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," McIlroy said.

"You are having to talk about it [his Friday performances] so it's in your mind and I am maybe putting more pressure on myself to shoot a good score.

"It's another Friday out of the way, thank God, and I can go on to the weekend. I shot 68 on the Friday at the US Open so hopefully next week will be the same."

Asked if he was shell-shocked, McIlroy added: "Yeah, because when I went to the gym in the morning the wind didn't seem as strong as it is now so I wasn't expecting this. Everything was tougher."

Shane Lowry fared much better with the conditions, carding a second-round 68 to end up two under par, where he was joined by Michael Hoey, who shot a second round of 74. 

Kevin Phelan and Darren Clarke ended the day level with McIlroy after second rounds of 73, and Damien McGrane and Padraig Harrington were a shot further back after second rounds of 72.

Gareth Maybin just made the cut mark of two-over with a 74 but Simon Thornton added a 72 to Thursday's 73 to end up three over, and Paul McGinley was two strokes further back after a second-round 73.

Peter Lawrie improved on his disastrous first day 79 with a one-over 72 but missed the cut by seven shots.