Earlier in June, the PGA Tour, DP World Tour and rival LIV circuit, which previously engaged in a bitter fight that divided golf, announced a merger to form a unified commercial entity.

"It looked to me like the PGA were total hypocrites when they cut a deal after they've been fighting them," the three-time Wimbledon champion said to ESPN on Wednesday.

The chairman of tennis's ATP Tour, Andrea Gaudenzi, told the Financial Times last week he has held discussions with Saudi Arabia's Public Investment Fund (PIF) and other potential investors on projects including infrastructure, events and technology investment.

Critics have accused Saudi Arabia of using the PIF to engage in "sportwashing" in the face of heavy criticism of the country's human rights record.

The 64-year-old McEnroe added that he was not surprised by Saudi interest in a possible investment in tennis, as the country has been spending heavily in other sports.

"What about (Cristiano) Ronaldo? He's being paid a couple hundred million a year. They have been buying players in other sports, brought boxing fights, you name it," he said.

"I wouldn't encourage it personally, the Saudi thing. I'm not surprised that tennis is being thrown into the mix after what we saw in golf.

"At the same time the people that are complaining about it, a lot of the people are hypocrites because our government does business with things along with tons of other hedge funds, wealth funds, down the list, people that have dealings."

Australian Open chief Craig Tiley believes any Saudi Arabian investment in tennis would not have the same impact as in golf.

Media reports say the country is bidding to host this year's ATP Next Gen Finals and world number one Carlos Alcaraz said earlier this week he would be open to competing there.