MEDINAH, Illinois, Aug 14 - Zach Johnson has a Ryder Cup dilemma going into this week's U.S. PGA Championship at Medinah Country Club.

The 30-year-old American is uncertain whether he should keep one eye on qualifying for next month's team competition while he plays in the final major of the year.

"That's something I've been battling with," Johnson told Reuters on Monday as he prepared for Thursday's opening round.

"But I think you have to think about it because it is one of your goals and those are good things to think about. Yet, at the same time, you've got to put it aside and get down to business.

"What's challenging and what I am relishing is the fact that it is in my mind. l've probably got to put it aside. I've got to work hard and just focus on the present rather than the future."

Johnson is ninth in the U.S. Cup standings with the top 10 at the end of this week automatically qualifying for the September 22-24 Ryder Cup at the K Club in Ireland.

However, his place is by no means certain and positions six to 10 in the table could change dramatically on Sunday.

Bob Tway, who languishes 103rd in the standings, would rocket into the top 10 should he triumph this week with 675 Cup points being awarded to the player who lifts the prized Wanamaker Trophy.

Johnson wasted a chance to all but secure his spot at last week's International when he slipped back into a tie for 13th after holding the lead going into Sunday's final round.

NO REGRETS

He has no regrets, though, over his performance at Castle Pines Golf Club in Colorado.

"The Ryder Cup is definitely my largest goal but at the same time I really feel like I've got one more week to earn that spot," said the Florida-based professional, whose only PGA Tour victory came at the 2004 BellSouth Classic.

"That's my perspective. I've got another week to win a golf tournament and I'm hoping this is the week.

"I played well at the International but, when it comes down to it, I had an opportunity to win and I just didn't perform the way I needed to perform at the end.

"I'm going to learn from it," added Johnson, who never recovered from a double bogey on his first hole in the final round and finished with 26 points, one fewer than he started the day.

Having narrowly missed out on Presidents Cup selection last year, Johnson is desperate to make his Ryder Cup debut.

"It would be huge," he said. "I wanted to make that team last year really bad but the Ryder Cup is the Ryder Cup.

"It's probably the largest event in golf as far I am concerned."