United States PGA Tour commissioner Jay Monahan has repeated his strong warning to players that they must follow protocol after five players withdrew from this weekend’s Travelers Championship due to Covid-19 issues.

One player, Cameron Champ, tested positive to the virus. Another two – Graeme McDowell and Brooks Koepka – are out because their caddies have the illness. Two more – Chase Koepka and Webb Simpson – withdrew because members of their family have been afflicted.

The withdrawals, coming immediately after Nick Watney’s WD because of a positive test at Hilton Head during the RBC Heritage last week, show how difficult the road ahead seems to be for professional golf in a pandemic. There have also been several positive tests from the secondary Korn Ferry Tour.

The difficulties are especially clear in America, where Covid-19 is still running strongly. It is the reason why Australia’s top-ranked player, Adam Scott, refused to make the trip to the USA to play the early events of the interrupted tour season. Tiger Woods has been another notable absentee thus far.

The European Tour and the LPGA Tour are still a few weeks away from resuming after the break forced by the pandemic. Soon enough the issues will be visited on Australia, with the Australian Open date still not finalised (due to be played at Kingston Heath later this year) and the Australian PGA Championship slotted for December in Queensland.

Golf Australia has said it will decide on the Open soon, while the PGA of Australia has locked in December 3-6 for the PGA.

“While we’ve been thorough in building and implementing a program that mitigates as much risk as possible, we knew it would be impossible to eliminate all risk, as evidenced by the three positive tests this week,” Monahan said. “We need to use these developments as a stark reminder for everyone involved as we continue to learn from an operational standpoint.

“We’re making several adjustments to our health and safety plan as noted in the memo sent to players this morning, and we will continuously reinforce to all players, caddies, staff members and support personnel on property at PGA Tour events to adhere to social distancing and other safety professionals that further minimize risk.”

Protocols have been strengthened this week with more tests and players required to wear masks in some instances, such as if they enter an equipment trailer. Monahan’s warning to players was blunt.

“All of us have an extraordinary responsibility to follow those protocols. For any individual that does not, there will be serious repercussions, and I’m not going to get into the specifics of it,” Monahan said. “But everybody knows and needs to know that our future, our ability to sustain this business and to impact the communities where we play and to create so many jobs is contingent on our ability to follow those protocols.”

Seven Australians -- Matt Jones, Cameron Davis, Marc Leishman, Cameron Percy, Jason Day, Greg Chalmers, Aaron Baddeley – are in this week’s field in Connecticut.