By Rory Carroll
SAN FRANCISCO (Reuters) - Jon Rahm's reign as world number one lasted just two weeks but the Spaniard said he expected turnover at the top to be the norm going forward with nobody dominating the sport right now.
Rahm rose to the top with a win at the Memorial Tournament on July 19 but quickly lost the crown when Justin Thomas won the WGC-FedEx St. Jude Invitational on Sunday.
"I think we are in an era right now where it's going to be hard to have somebody distance themselves," Rahm told reporters at TPC Harding Park in San Francisco where the first major of the year, the PGA Championship, kicks off on Thursday.
"When you have so many great players playing who go out at the same time, at any given point for two or three months one of us can get hot and take the number one spot. I think we might be entering an era where we bounce back and forth."
The 25-year-old, who has never won a major but has been knocking on the door in recent years including being tied for third at last year's U.S. Open, said it was an exciting time for golf and likened it to the battle at the top of men's tennis.
"You have Rafa (Nadal), (Novak) Djokovic and (Roger) Federer who are competing at the same time. Who is (going to be) number one? You don't know, it depends on who plays better that year.
"It's going to be hard to have a Tiger-esque case right now because there's so many players with so much talent and (they) are really, really good," he said, referring to the 44-year-old, 15-time major champion Tiger Woods.
"It could be a situation where we are going back and forth, and hopefully I'm the one that stays up there for awhile, but it's going to take a lot of good play."
Rahm will be grouped with fellow Spaniard Sergio Garcia and veteran Phil Mickelson for the first two rounds of the tournament, which is being held without fans in attendance to slow the spread of the novel coronavirus.
(Reporting by Rory Carroll; Editing by Ken Ferris)