MIAMI (AFP) - A US PGA Tour coronavirus policy change involving asymptomatic players allowed American Cameron Champ to enter the field for the Rocket Mortgage Classic that teed off Thursday (July 2) in Detroit.

The change began on Wednesday night involved players who test positive but show no symptoms of the deadly virus that forced a three-month tour shutdown before events resumed in June.

Since the return, all positive tests for players or caddies required a 10-day isolation period based on US Centres for Disease Control and Prevention (CDC) protocols.

After several asymptomatic positive tour tests followed by negative tests and following direct consultation with the CDC, the PGA decided to move forward within CDC guidelines allowing players and caddies who test positive but show no Covid-19 symptoms to return to competition if they have two negative tests at least 24 hours apart.

The immediate change enabled Champ to be added to the field for the Detroit Golf Club tournament hours before Thursday's opening round.

Champ tested positive on June 23 at last week's Travelers Championship but returned three negative tests in the 72 hours following the positive test.

Like all players, Champ would still have to test negative upon arrival at the course before his round.

"I am extremely grateful for the tireless efforts and conversations between the tour, my team and all of the experts who were consulted in order to deliver this best possible outcome," Champ said in a statement.

"It is a great example of everyone being committed to working together to adapt and evolve in this constantly changing environment."

Champ, 25, seeks his third PGA crown after taking the 2018 Sanderson Farms Championship and last year's Safeway Open, the third tournament of the restarted 2019-20 US PGA season.

PGA players Harris English and Chad Campbell, who tested positive earlier this week but were asymptomatic, will be eligible for next week's event in Dublin, Ohio, if they enter a test regime and return two negative tests at least 24 hours apart.

The same situation applies to two asymptomatic Korn Ferry developmental tour players who tested positive, Brandon Wu and Jonathan Hodge.