Geldenhuys, 33, was at the heart of a landmark RaboDirect PRO12 season for Zebre, who won their first-ever game in the competition back in September against Cardiff Blues.
The Italian side went on to record four more wins - but Geldenhuys and company have not fared so well on the international stage this season.
Since victory over Fiji in November Italy have lost eight times, including defeats to Samoa and Fiji earlier this month.
A fixture against Japan this Saturday is their last opportunity to buck that trend this summer, and Geldenhuys is convinced the Azzurri can finish on a high.
"We come from a series of defeats," said the South African-born lock.
"It's been difficult during a long season, but we know how important it is to finish the tour with a win so that we can enter the coming season with confidence.
"The pitch is very fast here at Chichibu Stadium and I'm sure this will help the two teams to play the game at a quick pace.
"It is an aspect we changed under (Italy head coach Jacques) Brunel - before we were a team that played mostly with our pack.
"We might risk a bit more now by keeping the ball alive and play quickly whenever possible."
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