Rory McIlroy struggles at Memorial

DUBLIN, Ohio -- Rory McIlroy's year of mediocrity continued Thursday at the Memorial Tournament, where the Northern Irishman is in danger of missing the cut after a 6-over 78, the worst opening round of his career.

McIlroy, who began 2013 amid much fanfare and was a strong No. 1 in the world, shot 40 for his first nine holes a week after missing the cut at the European Tour's flagship event, the BMW PGA Championship at Wentworth.

"I'm pretty frustrated," McIlroy said. "I'm trying not to let it get to me. I don't have any explanations for (the 78)."

Former Masters champion Charl Schwartzel was the leader after a 65 at Muirfield Village Golf Club.

Defending champion Tiger Woods carded a 71.

A year ago, McIlroy, 24, also missed consecutive cuts in these two events and also missed the cut at the U.S. Open before going on to win the PGA Championship by eight strokes and adding three other worldwide victories to capture the money titles on both the PGA Tour and European Tours.

But since winning the season-ending DP World Championship in Dubai, McIlroy has had more struggles than success.

"I'm fully focused on what I need to do," McIlroy said. "And I didn't think I played as bad as the score would say … I thought coming off the back end of last year, winning the PGA Championship, I wanted to do the same sort of things. It just hasn't happened. I haven't lived up to my own expectations."

He missed the cut in Abu Dhabi, got bounced from the first round of the WGC-Accenture Match Play, then withdrew during the second round of the Honda Classic, later admitting it was a mistake. This came in the aftermath of signing a lucrative endorsement contract with Nike to play its clubs.

Things settled down after the Honda, as McIlroy began to find some form, with top-10 finishes at the WGC-Cadillac Championship at a runner-up at the Texas Open.

After a tie for 25th at the Masters, McIlroy was tied for 10th at the Wells Fargo Championship and tied for eighth at the Players Championship, although not in contention over the final nine holes.

"I'm really excited and positive where my game is at," McIlroy said in England before the BMW last week. "It's just a matter of holing a few more putts and if I can do that, and keep giving myself chances to win tournaments, hopefully I'll walk through that door and get the first win of the season."

That is unlikely to happen here, and it puts in question his ability to be a contender in two weeks at the U.S. Open at Merion, a course he has yet to see. Issues over his management arrangement have come up in recent weeks, and he is now a distant No. 2 in the world to Woods, the defending Memorial champion.

Putting has been an issue for McIlroy this year. He ranks 94th on the PGA Tour in the strokes gained putting category and needed 33 putts on Thursday and hit just 11 greens in regulation.

A 5-footer for birdie on his last hole spun out and pretty much summed up his entire round.

"It's just not all there," McIlroy said. "It was a bit of a struggle out there."