Justin Spieth may not have lifted the Claret Jug on Sunday but the 2017 Open champion feels back to his best after a productive week at Carnoustie.

Spieth is yet to win in 2018 and he struggled to put himself in contention at the U.S. Open at Shinnecock Hills, where the American star missed the cut.

Retaining his Open title looked a distinct possibility as Spieth held a share of the lead heading into the final round, but a 76 on Sunday left him four shots adrift of eventual winner Francesco Molinari.

For the third time this week Spieth struggled on the final four holes, dropping another two shots to add to the three that went by the wayside on the front nine.

Despite the disappointment, Spieth found plenty to be happy with and feels ready to challenge for tournament wins again.

"I played patiently. I put good swings on it. Never got down on myself. Never got angry," he told reporters.

"I just didn't make a putt today. I hit really good putts too. My stroke is there. It's back, which feels awesome.

"And my game all together is back. I've had different parts of every single part of my game being at kind of a low point in my career, not all at the same time, but enough to where I haven't really been able to compete. 

"It's all there, and it's moving in the right direction. So, I'm actually very pleased coming out of this week.

"I believe that my best golf has yet to come, absolutely. Even better than 2015, all that, yeah. 

"I believe that going through struggles, you start to realise where your tendencies are and how to -- you know, how to compensate for it and turn them into advantages. I think that I have that going for me."

Spieth was not the only one to find positives out of Sunday's round, joint-runner-up Xander Schauffele was happy with his best major performance despite slipping out of contention late on.

"It's just going to go in the memory bank as a positive," said the 24-year-old. "I had a chance to win a major championship. I was in the final group. I had to face a little bit of adversity early in the round, and I still gave myself a chance.

"So I can look at it - anyone can look at it however they want to, but I'm going to look at it as a positive moving forward, and try to learn how to handle the situations a little better next time."