Massimiliano Allegri said Juventus had "heavy legs" after beating the A-League All-Stars side 3-2 in Sydney on Sunday.
The hosts - who boasted Juve legend Alessandro Del Piero in their ranks - took the lead through Marcelo Carrusca on nine minutes, before Fernando Llorente levelled in the second half.
But the Bianconeri again fell behind when Tomi Juric found the back of the net on 77 minutes, only to be saved by late goals from Paul Pogba and Simone Pepe.
The game was part of Juve's Asia-Pacific tour and Allegri admitted his players were feeling the physical effects of several days of tough work.
He said: "We made too many mistakes, at an individual level and not just in defence. But the boys had heavy legs because of the hard work done in Sydney over the last two days.
"Of course, we still lack a bit of rhythm before we start Serie A but we are working well and working hard to get there."
Juve kick off the defence of their Serie A title with a clash against Chievo on August 30.