The tourists were beaten by 13 runs in the first game at Hobart on Wednesday, but Hales believes that the team have shown before that they can recover from disappointment.
"It's a huge game, any international game of cricket is, particularly playing at the MCG in front of what is going to be a huge crowd," Hales told reporters. "It's a must-win game for this series.
"In the last few series where we've lost the first game against India and then we bounced back well.
"We lost against Australia in the first game during the summer and bounced back well. As a squad we are still very confident in what can happen in these two games."
You can follow live text coverage of the game on Sports Mole from 8am on Friday.