(CNN) -- After winning the BMW PGA Championship in England in late May, Rory McIlroy missed the cut at his next European event, the Irish Open, last month.
The Scottish Open is mirroring the former No. 1's inconsistent season.
McIlroy produced a superb, course-record 64 in chilly, windy conditions at Royal Aberdeen on Thursday -- it included a staggering 430-yard drive -- but then imploded Friday, registering a 7-over-par 78. He is six shots behind leaders Kristoffer Broberg, Marc Warren and Ricardo Gonzalez.
It was one of the biggest turnarounds you're bound to see -- but in keeping with his second-round woes.
At 13 stroke-play events this season, he has failed to hit under 70 in the second round nine times and his average stands at 72.2, noted the Golf Channel.
"I'd be much happier standing here after a couple of 71s, but that's not the case,'' McIlroy told reporters. "It hasn't been the case all year.
"I get off to a good start and then I just fall away. But I'm still in the tournament and I can go out in the morning and try and get a few of those shots back that I lost today.
"I need to try and hold it together somewhat.
McIlroy's front nine, though not good, wasn't terrible. He mixed three bogeys with one birdie. But on the back nine he didn't hit a birdie and struck a double bogey and three bogeys.
From being in an outstanding position Thursday, he wasn't far off missing another cut.
It's not the round he would have wanted with the British Open taking place next week.
"It's another Friday out of the way," McIlroy said. "Now I can go onto the weekend."
Phil Mickelson, the other marquee name at the event, dipped, too. Last year's Scottish and British Open winner was five shots worse in the second round, carding a 73.
"I'm a little concerned that it's taking up a little more energy than I would like for next week, but it's also a good opportunity to focus on some of the difficult shots that we'll have next week, so it kind of goes both ways," Mickelson said in a TV interview shown by Sky.
Mickelson is five shots off the pace.
Wie misses cut
It won't be two majors in a row for Michelle Wie.
Wie, the much hyped American, missed the cut at the women's British Open at Royal Birkdale in Southport, England less than a month after claiming her first major, the U.S. Open.
The 24-year-old followed up her 75 Thursday with a 78 Friday, undone by six birdies and a double bogey.
"I missed a lot of greens," Wie, who turned pro aged 15, told reporters. "I had a lot of hard par putts today, and I didn't make them. I didn't do much on any of the holes. It didn't go quite as well as I wanted it to."
Another American, Mo Martin, leads at the halfway stage by three shots over Spain's Beatriz Recari.
Overnight leader Ayako Uehara crashed to a 79 and trails Martin by nine shots.