Coronavirus: World No.1 golfer Dustin Johnson, football star Cristiano Ronaldo among latest positive tests

Two of world sport's biggest names - footballer Cristiano Ronaldo and golfer Dustin Johnson - have joined the 38 million reported COVID-19 cases around the world.

World No.1 Johnson, who last competed at September's US Open, has withdrawn from this week's CJ Cup on the PGA Tour in light of the diagnosis, as he begins to self-isolate.

"Obviously, I am very disappointed," says Johnson, 36. "I was really looking forward to competing this week, but will do everything I can to return as quickly as possible.

"I have already had a few calls with the tour's medical team, and appreciate all the support and guidance they have given me."

Johnson has had a sensational year, winning his first FedExCup championship at East Lake last month, before taking home PGA Tour Player of the Year honours for the second time. 

The news comes one week after American Tony Finau was forced to withdraw from the Shriners Hospitals for Children Open, after testing positive for the virus, which has killed more than 215,000 people in the United States. Finau will not compete at the CJ Cup either.

Meanwhile, Juventus Ronaldo striker will miss this week's UEFA Nations League game against Sweden, but is "well, has no symptoms and is in isolation", says the Portugal Football Federation.

The rest of the Portugal squad have undergone tests as a result of Ronaldo's positive, but they have all tested negative and will be available for the Sweden match.

Five-time World Player of the Year Ronaldo, 35, appeared in his side's 0-0 draw away to France in the Nations League on Sunday and Wednesday's 0-0 draw in a friendly at home to Spain.

He will now be doubtful for Juve's Serie A trip to Crotone on Saturday and their Champions League group stage opening game away to Dynamo Kiev next Tuesday. 

Elsewhere, two teams have withdrawn from the Giro d'Italia, after returning positive coronavirus tests on the first rest day of the Grand Tour.

Australian Mitchelton-Scott outfit had four positive outcomes among their staff, after losing their top rider, Simon Yates, last week.

Jumbo-Visma - the team of Kiwi George Bennett - also withdraw, after leader Steven Kruijswijk tested positive. Bennett is not contesting the Giro, after completing the Tour de France last month.

Reuters/Newshub