According to Sport24, the Australians had already planned to recall opener Phil Hughes in place of Shaun Marsh, who is ruled out after hurting his hamstring in the fourth one-dayer, and they may now need to replace Clarke as well.
England levelled the series at 1-1 in Cardiff on Saturday, setting up the prospect of an exciting finale, and Clarke is still hoping to play, the report said.
However, coach Darren Lehmann insisted Clarke would only be allowed to play if he is fully fit for the match in Southampton, the report added.
Lehmann said that it was a big game but if Clarke could not be fit, the team would not risk him, adding that the team had another important series coming up against India and an Ashes series.
Should Clarke be unavailable, Australia may call all-rounder Glenn Maxwell into their squad for the first time in the series, with leg-spinner Fawad Ahmed another option, the report further said.
Australia has endured a disappointing tour, an early exit in the Champions Trophy followed by a 3-0 Ashes defeat and then a 1-1 draw in two Twenty20s, according to the report.
--ANI (Posted on 16-09-2013)