Joe Root's squad left England without vice-captain Stokes who remains at home awaiting the outcome of a police probe into his involvement in a brawl outside a Bristol nightclub on September 25.
The England and Wales Cricket Board have not yet ruled key man Stokes out of the Ashes series, which starts with the first Test in Brisbane on November 23.
"The situation in a word is complicated," Strauss, the ECB's director of England cricket, told BBC Radio on Sunday.
"There's two different potential disciplinary procedures he has to go through, one is the ECB's own internal one and the other is any potential police action," the former England captain added.
"Until we know more from the police it's very hard for us to put a timeline on anything.
"What we all want is clarity on what that situation is and how much cricket he will be missing for England. We're keen to get into that and move this forward but we're in the hands of the police.
"Ben has been and is developing into a world-class cricketer. The fact he's not out there at the moment is a blow to the England team."
Strauss was the last England captain to lead the side to a Test series win in Australia, overseeing a 3-1 victory in 2010/11.
England hold the Ashes following their 3-2 home success in 2015 but their most recent tour of Australia ended in a humiliating 5-0 defeat in 2013/14.
Strauss said the memory of that whitewash would spur those on the receiving end, such as current captain Root, to greater heights now.
"I was involved in a 5-0 drubbing in 2006 and I used that as a very strong base for retribution," said Strauss. "I'm sure the guys who were there last time and suffered the chastening defeat at the hands of Mitchell Johnson will want to put that right."
First Published: November 5, 2017, 11:12 PM IST