If he fails to make the halfway cut in his latest tournament, it will also be the third straight time he has failed to play the weekend at the Irish Open, but McIlroy is determined to avoid that fate.
"I'm not sure what I'm going to need to make it into the weekend, but obviously I would love to be here for that. So I've just got to get out there and play a bit better," he told the official European Tour website.
"It's disappointing, but you know, I just need to pick myself back up and get out there tomorrow and try and shoot a good one."
McIlroy's efforts were in contrast to the superb 67 posted by another home hope, Padraig Harrington, the 43-year-old Irishman running up five birdies in six holes from the 11th in afternoon play.
Harrington, who scored a comeback win at the Honda Classic on the PGA Tour earlier this year, is bidding to add to his 2007 Irish Open victory.