But with Munster's scrum going backwards in recent weeks against Toulon and the Ospreys, while Leinster held their own against Clermont, Ross will finally get his chance to add to his two caps.
The former Harlequins man has been criticised in the past for his lack of movement around the park but Smal was quick to praise the improvement he has made since returning to Ireland.
"I think for the last two years he has improved himself dramatically," said Smal, who was on the coaching staff of South Africa's victorious 2007 World Cup campaign.
"He's a good scrummager and he has worked on his general play.
"His general plan is to see how big an impact he can have."
Kidney will also welcome back Paul O'Connell - the Munster star finally over his groin injury.
This will come as a boost to the Irish lineout and restarts, which really struggled in November when they kick off their campaign against Italy in Rome on Saturday before entertaining France at the Aviva Stadium a week later.