Published Saturday, 14 September 2013
McIlroy has not won a championship since November last year. (© Getty)
The Holywood golfer carded a 77 on Friday to put him on 13 over par and 70th overall in the tournament.
McIlroy's round, despite being an improvement on a first round 78, included six bogeys, one double bogey and two birdies.
It is the worst two-round aggregate score the Northern Irishman has recorded over two rounds in the US.
Current world number four McIlroy told PGA.COM: "I'm just not scoring well. I missed it on the wrong side, I'm missing greens with wedges, and just not just don't have my scoring hat on.
"I felt really good after the PGA. I feel like when I've actually gotten myself into contention, that's what I've played my best this year.
"When I've actually had a little bit of pressure, that's when I've actually played my best, so that's a good sign.
"The bad sign is that I'm not in contention too much.
"But yeah, it's frustrating, but I'm trying to stay as patient as I can."
Graeme McDowell, meanwhile, lies one over par in the tournament.
McDowell carded a 73 on Friday and sits tied in 35th in the preceedings.
There is no halfway cut in the championship, however, the top 30 players will go on to qualify for the Tour Championship FedEx Cup in Atlanta, where the winner will claim a $10m (£6.3m) prize pot.
© UTV News