If either Wade or Khawaja is dumped, Hilton Cartwright could come into the side to provide another batting option and support Pat Cummins with his medium pace.
Australia, trying to save the series, deployed a three-pronged spin attack with Steve O'Keefe replacing injured fast bowler Josh Hazlewood.
"Even though worldwide cricketers are fully professional and play almost all year round, Australia's failure was more to do with not playing any competitive cricket in the lead up to the Test series", Chappell wrote in a column for Hindustan Times.
The final piece of the puzzle is the position of wicketkeeper, with some reports saying Matthew Wade could make way for part-time keeper Peter Handscombe.
More than a third of Bangladesh is under water after strong, consistent rains in the monsoon season and the location of the second Test, Chittagong on the southeast coast, is expected to be battered by heavy rain and thunderstorms.
The uncertain weather has contributed to Australia's selection headaches as they fight desperately to square the ledger against a Bangladesh side ranked ninth in the world. Rain is forecast for all five days but the silver lining for cricket fans is that, according to the Bangladesh Meteorological Department, showers are not likely to be lengthy enough to cause major delays.
"It certainly can come into it", Smith said.
"It is a morale boost".
With Bangladesh 1-0 up after their 20-run win in Mirpur last Wednesday, even a draw will give the hosts their maiden series win over Australia and a promotion to number eight in the ICC rankings. They are a professional side so they know what they have to do.
It is the first time since their only previous Test at Chittagong more than 11 years ago that Australia have picked three spinners. They are probably under pressure but it doesn't mean they will lose.