Golf Digest has reported the tournament, scheduled for June 10 to 13 at St. George’s Golf & Country Club in Toronto, is set to be cancelled in the coming weeks. 

It is thought the current border restrictions between the United States and Canada would make it difficult for players, caddies and other personnel to travel to the event, particularly due to the quarantine period that is mandatory for those moving between the two countries. 

Even if participants were exempt from quarantine, there would still be logistical and financial challenges for organisers.

Financial issues would arise from a lack of spectators at the event, for example. 

Hopes of holding the tournament decreased further this week when the City of Toronto extended a cancellation of major in-person events until July 1. 

The RBC Canadian Open is a private event so is exempt from the ruling, but organisers would reportedly struggle without assistance from local Government. 

"We are aware of the city of Toronto’s decision to cancel permits for large-scale public events through July 1 of 2021 due to the ongoing COVID-19 pandemic," a PGA Tour spokesperson told Golf Digest. 

"We respect the city of Toronto’s decision as health and safety in the communities we play remains our number one priority. 

"With the 2021 RBC Canadian Open being in the window of the city’s cancelled permits, we are working with our partners RBC and Golf Canada to determine the best course of action."

If the RBC Canadian Open was cancelled, it would be for the second consecutive year. 

Last year's event was also called off, with the PGA Tour severely disrupted by the pandemic. 

The RBC Canadian Open is the third oldest tournament on the PGA Tour currently running, behind only the Open Championship and the US Open.

Northern Ireland's Rory McIlroy won the 2019 edition of the event at Hamilton Golf and Country Club in Ancaster in Ontario.