Reverse-swing looms as the factor that will decide whether Australia escape with a draw from the fourth Ashes Test.
Steve Smith's side will resume at 2-103 on day five of the MCG match after rain washed out approximately one and a half sessions on day four.
Australia trail by 61 runs, with coach Darren Lehmann having admitted on day three their hopes of a whitewash are all but over.
Smith and David Warner's unbeaten partnership has lasted 22.4 overs but featured only 38 runs.
The slow pitch has offered bowlers from both sides limited assistance, with reverse-swing generally the most potent ploy.
'There's not a lot you can do on a wicket such as this," England coach Trevor Bayliss said.
"Both teams were able to reverse the ball at different times.
"Both teams had it going a little bit. It wasn't going big but it was doing a bit ... we had them in a bit of trouble."
Lehmann noted "the ball is obviously reversing, it is tough work for a new batter so once you are in you have to stay in".
Both sides have been cautioned by umpires about deliberately throwing the ball into the abrasive centre-wicket block, a tactic that is frowned upon but widely employed in an effort to scuff the ball and make it go reverse.
Bayliss came out swinging in response to ball-tampering reports that centred around footage of Jimmy Anderson cleaning the ball, saying it was a "beat-up" and "Pommy bashing".
First-innings centurion Warner reined in his natural aggression on Friday.
Warner is 40 not out from 140 balls, having faced more maidens in this dig than any other of his Test innings.
"He's one of the best batsmen in the world. It was great to see him bat the way he did for the team," allrounder Mitch Marsh said.
"There's been three draws in Sheffield Shield cricket here this year, hopefully there's another one tomorrow."
Marsh agreed with Lehmann and Bayliss' words about reverse-swing.
"Victoria have shown over a long period of time that if you can get the ball shifting throughout the game, it's vital," Marsh said.
