Arthur revealed that he was planning for retired pair Ricky Ponting and Michael Hussey to be part of his top six for the Ashes, and as a consequence the India tour has meant that he has had to find a different top order.
"[This series compared to the Ashes] is probably not that fair a barometer," Cricinfo quotes Arthur as saying. "I was pretty scared when I looked at the schedule because we'd been building a top six and a team.
"We were nearly the finished article, then we lose 300 Test caps. In my thinking Ponting and Hussey were coming to the Ashes. We had them pencilled in to come to the Ashes so we had some stability in the top six.
"We thought we had experience, some good young players and it was the perfect blend. We then lose both those players. We can't go into the Ashes thinking 'what's our best top six?' We can't be using the first couple of games as a trial."
Australia are currently 2-0 down in their tour of India.