The US PGA Tour has cancelled The Players at Sawgrass a round in, as well as the following three tournaments, in response to growing fears over the Coronavirus.

The tour announced Thursday night (US time) that the $US15 million so-called 'fifth major' would not continue, despite one round already having been played with a crowd in the venue at Ponta Vedra Beach.

Initially, the tour said following the first round's play that the remainder of the tournament would go ahead without crowds being admitted.

But late Thursday night the tour changed its mind.

"We have pledged from the start to be responsible, thoughtful and transparent with our decision process," it said in an official statement. "We did everything possible to create a safe environment for our players in order to continue the event throughout the weekend, and we were endeavoring to give our fans a much-needed respite from the current climate.

"But at this point – and as the situation continues to rapidly change – the right thing to do for our players and our fans is to pause."

The tournaments impacted beyond The Players are the Texas Open, the World Golf Championship matchplay and the Corales Resort Championship. No statement has been made about The Masters tournament, which is the week after Corales.

The LPGA Tour also has postponed its next three schedule tournaments.

Japan's Hideki Matsuyama with an opening 63 was the first-rounder leader at Sawgrass, and Australian Marc Leishman at 67 was in the mix.

Leishman eagled his last hole, the ninth on the course, hitting two pure golf shots and then burying his putt from seven metres to finish five-under par, four from the lead.

Jason Day took his place in the field despite his back issues, but struggled to a four-over 76 with just one birdie, revealing later that he had undergone minor back surgery to relieve the pain that forced him to withdraw last week.

World No. 1 Rory McIlroy opened with a stuttering even-par 72.