KUALA LUMPUR - Lexi Thompson's brother Nicholas Wednesday said Kiwi star Lydia Ko would shine as a professional golfer despite making the switch at the age of just 16.
Ko, who has already won four professional tournaments as an amateur, announced her long-awaited decision by tweeting a YouTube clip also featuring rugby star Israel Dagg.
Ko had previously planned to complete her education and go to university in the United States before taking up a professional career.
A cautionary tale comes from Michelle Wie, who turned professional amid great fanfare just before her 16th birthday but has since struggled to live up to the hype.
But Thompson, who plays on the PGA Tour, said Ko had similar attributes to his 18-year-old sister, Lexi, who has been a success since turning pro at 15.
"She's played unbelievable, and she's very deserving of turning pro no matter what her age is," Thompson said of Ko, ahead of this week's $7 million CIMB Classic in Kuala Lumpur.
"I know she's proved herself over and over against the ladies, and she's obviously proved mentally that she can do it and physically.
"So it's the same case as my sister, where it's time. They're mature beyond their age and they're ready to go."
Thompson will play at Kuala Lumpur Golf and Country Club just over a week after his sister won the Sime Darby LPGA Malaysia at the same venue, her second career victory.
He said Lexi and Ko were different from Wie because they had eased their way into pro golf and had not tried to play men's events.
"My sister had really no intentions of chasing men's events or anything of that nature," he said.
"She didn't just jump in head-first and play 24 events that year," Thompson added.
"It was a very small, limited schedule and I think that helped, dipping her toe in the water and getting her ready for it."
Ko, who last year became the youngest winner of a professional golf event aged 14, is ranked fourth in the world and has missed out on more than $2 million in prize money because of her amateur status.
In her YouTube video, she said she plans to make her professional debut at next month's LPGA season finale in Florida.