Reigning champion Jordan Spieth believes Tommy Fleetwood could be the biggest threat at next month's British Open after a sensational second place at Shinnecock Hills last week.
Spieth was a mere spectator as Englishman Fleetwood fired a magnificent final-round 63 to match the lowest round in US Open history and almost snatch victory.
Fleetwood had to be content with the runners-up spot, one stroke behind American Brooks Koepka, but Spieth said he could carry that momentum into Carnoustie when the tournament starts on July 20.
"A 63 on Sunday, he had a few putts at 62 I know he wishes he could get back, but 63 on a Sunday at a US Open is absurd," Spieth, who missed the cut after a first-round 78, said in a conference call on Wednesday.
"It's unheard of. It's a fantastic round, and I don't think anybody was surprised, any Tour player was surprised that Tommy Fleetwood did it.
"He certainly has the game, the capabilities, and somebody who has proven he's not afraid of the moment of the shot. I can certainly see him as one of the favourites, somebody who will have a lot of momentum if he works his way up to the lead."
After the brutal test of the US Open where no player finished under par after four rounds, Spieth is expecting no less of a challenge at Carnoustie - a course that has inflicted its fair share of pain in the past.
"I've seen Opens at Carnoustie. I've seen why the golf course has a reputation and a nickname, 'Car-nasty', among a lot of the players, for being that difficult," the American said.
"Although it won't be necessarily the golf course itself; the conditions can obviously create scores similar to what the US Open just saw. But I thoroughly enjoy links golf."
Three-times major winner Spieth, 24, is yet to win on Tour this year but said he was not concerned with his form heading towards the attempted defence of the Claret Jug.
"Its been an off year. The results haven't been up to my own expectations, and its been putting the majority of the year," he said.
"But I have no doubt in my ability to come back and defend whether form's on, off or anything indifferent. I've proven to myself that I can go from two missed cuts to potentially winning the week after in previous years."
Spieth is in action at the Travelers Championship this week in Connecticut.