Jeju - Justin Thomas said on Thursday a fit Tiger Woods should be on the US Presidents Cup team "100 times out of 100" as the debate about who should get a wildcard heats up.

The PGA Tour has decamped to Asia for this week's CJ Cup in South Korea and next week's Zozo Championship in Japan, where Masters champion Woods will make his comeback from arthroscopic knee surgery.

A week later after the WGC-HSBC in Shanghai, Woods will announce his four captain's picks to face Ernie Els's International team at Royal Melbourne Golf Club in December.

The consensus is that if Woods is fit, then he should make himself the first playing captain since Hale Irwin at the inaugural Presidents Cup in 1994.

"I think if he's healthy and playing well, I mean, I'll take him, you know, 100 times out of 100," world number five Thomas told Australian media in a conference call from Nine Bridges Golf Club.

"I think he knows his body and knows himself well enough to make that decision."

Thomas won the inaugural CJ Cup two years ago and Thursday he carded an opening four-under par 68 to be handily placed in a gaggle of 14 players within four strokes of leader An Byeong-hun.

"It was a good day. I got off to a good start," Thomas, who began on the 10th, told reporters, adding that he was disappointed to par his last five holes after a bogey six at the 18th.

"I felt like I could have made a couple more birdies. Today could have easily been a seven or eight under, but still a good start."

US Open champion Gary Woodland, another 2019 major winner needing a nod from Woods, shot a 71 for a share of 39th in the 78-player field.

Jordan Spieth shot an two-under 70 as he tries to sneak into the reckoning.

Patrick Reed, Tony Finau and Kevin Kisner are also in the running, but they will not make their seasonal debuts until next week at Accordia Golf Narashino.

Newlywed Rickie Fowler is on honeymoon and skipping the Asian swing, but is believed a certainty to be on the plane to Australia.

Thomas doesn't envy the conundrum facing Woods with so many great names to choose from.

"It shows how deep our team is and how many great players we truly have," said Thomas, who had a successful partnership with his good pal Spieth at last year's Ryder Cup.

"You know, he's going to make the right decisions. He's going to do what's best for the team, not what's best for him or what's best for one individual.

"I know that I'm very excited to play for him. I mean, if you would have told me when I was a kid that I could play on a Presidents Cup team with Tiger Woods as my captain, I probably would have fainted."