HOUSTON - Jordan Spieth insists he has headed into prior Masters in "lower" form than the current crestfallen nature of his golf game.

The 24-year old Dallas native tees it up this week on Lone Star State home soil in the Houston Open not having tasted success since capturing last year's Travelers Championship in Connecticut and then collecting a third Major victory at The Open championship at Royal Birkdale. Spieth did go close to victory in the opening two events of last year's FedEx Play-Off Series, losing a play-off to Dustin Johnson for the Northern Trust Open and finishing runner up in the following Dell Technologies. However, in nine PGA Tour events in 2018, Spieth has finished no higher than ninth, missing two halfway cuts along the way.

He has dropped fourth in the world rankings, but said he's felt worse about his chances heading into the first major of the year, which tees off at Augusta National next week. "I've gone into Augusta feeling lower than I am right this second about my ability to compete, or the ability to get into contention and win and still been in the last group or last couple groups," he said.

"In 2016 I was hitting it horrendously going into Augusta. I'm striking the ball a lot better now. I just putted extremely well starting from the first round at Augusta in '16. "I came off missed cuts here I think in '14 and '17 and was in the last group, second-to-last group come Sunday with a chance to win. "In order for me to really feel like at my highest level of confidence I need to be able to compete next week, it doesn't make a difference what happens here."

Spieth will tee-up in his fifth Masters having sandwiched runner-up finishes in 2014 and 2016 around his Augusta victory in 2015 -- the first of his three major titles.

  Given his downturn in form, Spieth was asked if he felt more at ease in not being mentioned as an Augusta favourite. "No, it doesn't make a difference to me at all," he said. "I don't care either way. We believe that if we go about our step-by-step goal and check all the boxes next week, then we'll have a chance to win."

Asked who he thought had the most pressure on his shoulders next week, Spieth singled out Rory McIlroy -- who needs only a Masters title to complete his Grand Slam collection. "Actually, there's nobody who should really feel any pressure on them, but I would say Rory has the chance to win the career Grand Slam," Spieth said. "That's something that he truly wants and so if there's one week a year that if he said he could win one tournament at the beginning of every year, he'll probably pick Augusta, and therefore he puts more emphasis on it."