Federer is aiming to win his 20th Grand Slam title later today after reaching a record seventh Australian Open final.
In order to do so, he will have to overcome Cilic who has already beaten world No 1 Rafael Nadal this tournament.
Federer and Cilic have met nine times throughout their professional careers, with the latter winning just one back in the 2014 US Open.
However, McEnroe opted to look back at one of the more recent encounters between the pair.
This will be a repeat of the 2017 Wimbledon final when Federer lifted his eighth SW19 title.
Cilic broke down in tears on court as blisters on his feet prevented him from giving the 36-year-old a fierce match.
“A little while ago, a goat (G.O.A.T) named Roger was happily browsing in an English grass field,” McEnroe said on Eurosport.
“Then came a tall Croatian shepherd who wanted to play with the animal.
“But Roger the GOAT made the shepherd run so much that it took the skin off his feet. He started crying uncontrollably.
“Months later, Roger the GOAT had moved to the Australian bush. This time a Korean whizz-kid thought that he could outsmart the animal.
“He too ran miles before his feet literally burnt under him.
“Hidden behind a tree, the Croatian shepherd was lurking in the shadow, fuelled by a desire for revenge.
“Don’t mess with Roger the GOAT, he has the power to give you blisters, again. That’s the moral of the story.”