US PGA Spieth's 'toughest' major test

American Jordan Spieth

Jordan Spieth is happy to wait for a career Grand Slam, but admits the US PGA Championship shapes as being tough for him to win.

The American three-time major winner carded a third straight round in the 70s at Quail Hollow, shooting an even-par 71 on Saturday.

Spieth, 24, was aiming to become the youngest player to win the career Grand Slam, but he sits at three over and is set to have to wait to complete the set.

While he has always wanted to win all four majors, Spieth said he felt the US PGA would be the most difficult.

"I didn't have it written in a diary from when I was young that I need to win a career Grand Slam as the youngest ever. That wasn't the goal," he said.

"The goal was to try and win them all. The goal was to try and get on the PGA Tour and then from there see what happens. And yeah, I have a lot of opportunities.

.@JordanSpieth with some INCREDIBLE touch!#PGAChamp pic.twitter.com/Q87dRCRLTZ

— PGA TOUR (@PGATOUR) August 12, 2017

"The PGA Championship I think is going to be the toughest for me. If we look historically back on my career, I think I will play this tournament worse than the other three majors just in the way that it's set up.

"I feel like my game truly suits the other three majors maybe more than a PGA Championship. But I believe we can play anywhere and can win anywhere.

"It's just a matter of having everything in sync at the right time."

Spieth missed the cut in his first two appearances at the US PGA before finishing second in 2015 and tied for 13th last year.