Long final sets have been ditched at the tournament in Melbourne, where first-to-10 tiebreaks are being used at 6-6 in deciding sets to bring matches to a close.
This year's Wimbledon championships will use a regular first-to-seven tiebreak at 12-12 in deciding sets -- a move brought in after last year's semi-final saw Kevin Anderson beat John Isner 26-24 in the fifth set.
That six hour 36 minute epic played havoc with the final weekend schedule and left Anderson in no fit shape to take on Novak Djokovic in the final.
While a tiebreak (first to seven) has long been the preferred system for final sets at the U.S. Open, the French Open will continue to allow matches to run and run at least this year before, inevitably, the organisers have another look.
"So this guy or this girl, they are tennis players, right?" former world number one McEnroe said.
"They are at the Australian Open and the score is 6-6 in the fifth for him or in the third for her. And suddenly, they start panicking... what's next? Is there a tiebreaker? If there is a tiebreaker, is it at 6 games all or 12 all?
"And if there is a tiebreaker, is it first to seven points? Or first to 10 points? 6-6? 10-10? 12-12? Where am I? Paris, New York? London, Melbourne? What do I do? Who am I?"
McEnroe pointed to British player Katie Boulter's premature celebration in her first round match against Ekaterina Makarova, having reached seven points in the third-set tiebreak.
After realising that she still needed another three points she refocused and got the job done.
But it is not hard to see the situation cropping up again.
"Four Grand Slams and four different rules to conclude the fifth set! Hello? Is there a federation here, someone who is supposed to harmonise this kind of thing," McEnroe added.
With the International Tennis Federation's (ITF) revamped Davis Cup, set to start in November, facing competition from the newly-branded ATP Cup, McEnroe says it is another example of the governing bodies not singing off the same hymn sheet.
"More than ever, this sport needs guidance and vision. Someone who can think beyond the childish rivalries between, the ATP, WTA, ITF, Grand Slams," McEnroe said.
(Reporting by Martyn Herman; Editing by Ken Ferris)
