Rhys Ruddock is relishing another physical battle with Georgia after his starring role as a late-comer to Ireland's victory over South Africa.

The Leinster back-row, who is 24 on Thursday, learned he would be starting at openside flanker at breakfast last Saturday morning after Chris Henry suffered a severe migraine.

Ruddock seized his opportunity, scoring his first Ireland try on his fourth appearance, and now is looking ahead to taking on a pedigree Georgia pack with most experienced in France's Top 14.

"They want to get up, meet you head on and win the physical battle," Ruddock said.

"They've got some real threats on the ball who can punish you if you don't get your roles right.

"You have to meet it head on in the early stages of the game, don't let them build confidence in their perceived strength and after that hopefully have some ways to work outside of those lines and try to create a bit of space elsewhere.

"Hopefully we'll have some ways to break them down. If you're just going to run straight and hard at them all day, they'll be well able to defend.

"We need to come up with some ways to create some space."

Ireland head coach Joe Schmidt found plenty to improve on after the Springboks display to ensure there will be no complacency on Sunday.

"They've got some real threats on the ball who can punish you if you don't get your roles right."

"Everyone's got a lot of respect for them," Ruddock added.

"Everyone's got a bit more confidence after a good win, but Joe's brought us back down to earth and the reality is we didn't perform to the best of our ability.

"It was a good win, but there's a lot more left in the tank. The focus now is on getting all of that out this weekend. We're hoping to improve our performance on last weekend."

Ruddock was thrust into the starting line-up after some time on the periphery with Ireland and Leinster.

"It was a little bit of a shock getting the start (but) I was more than ready," added Ruddock, who is more often a blindside flanker.

"Around breakfast time I found out and I was happy to be starting, playing seven.

"I got my head round playing seven nice and early. I knew I was covering it anyway from the bench. I was able to narrow my focus and concentrate on that role."

Ruddock is the son of former Wales head coach Mike Ruddock but was born in Dublin and pledged his allegiance to Ireland.

He made his Test debut in Australia in 2010 and had to wait nearly four years for his next opportunity, coming off the bench against Italy in the 2014 Six Nations, before a first start in Argentina in June.

With the benefit of hindsight, he is glad to have been patient.

"I had to take a good hard look and work out what was best for me, in terms of my career, and whether or not staying at Leinster would allow me to develop," Ruddock added.

"After weighing up all the options I decided what I could learn at the club and within the Irish system was more beneficial than me going elsewhere and maybe getting a bit more game time.

"Possibly in other teams maybe I would've been getting a bit more game-time, but I had to bide my time and learn from the expertise that was around me.

"I'm glad I made the decisions I made and I'm enjoying getting a bit more game-time now these days."

Among the experiences was captaining Emerging Ireland in the 2013 Tbilisi Cup, including against Georgia.

Ruddock added: "That was a great experience. The Georgia one was a great win for us. We managed to perform well.

"It was a real physical encounter and probably our toughest game of the tournament, against a Georgian team who have a lot of pride in playing for their country and a lot of pride in being a physical outfit who can take anyone on, especially up front."