South Africa have called up out-half Handre Pollard to their World Cup squad as an injury replacement, significantly strengthening their selection ahead of Saturday's Pool B showdown with Ireland, after injury forced them to leave him out initially.

Pollard, who helped kick South Africa to World Cup success four years ago, replaces hooker Malcolm Marx.

Marx suffered a serious knee injury in training last week.

South Africa's coaching team watched Pollard in action for Leicester Tigers in a friendly against Sale Sharks on Friday, deeming him fit enough to return and choosing a proven kicker instead of a replacement hooker.

"We are confident with the cover we have at hooker with Bongi Mbonambi and Deon Fourie, and Marco van Staden has been slotting in the position since our alignment camps in February, so we opted to call up Handre, who has been in our system for years and who was a member of our team in 2019 when we won the World Cup," said coach Jacques Nienaber.

"He's been working hard to return to full fitness, and we are pleased that he now has some game time under his belt for his club, and this will allow him to slot back into the team.

"We’ll work closely with him in the next week to get him back up to speed and back into the full swing of things, and we have no doubt he’ll step up to the challenge. He’s been here before so he knows the physical and mental demands of the World Cup."

The Boks had a fine day at the office on Sunday, thumping Romania 76-0, but there is concern about another possible injury in their squad as Vincent Koch missed out after hurting himself in the pre-match warm-up.

Nienaber said the prop hurt his knee but the extent of the injury was not yet clear.

"There is a bit of injury worry within the side so we will look and assess and make a decision," he said.

South Africa face Ireland at the Stade de France in Paris in a match likely to settle the top two in the pool and decide who plays France or New Zealand in the quarter-final, barring any major upsets.

"We've got a short turnaround, so we'll enjoy tonight but in a controlled manner and we'll start making plans for Ireland tomorrow," added Nienaber.

"It will be a big game in terms of who finishes one or two in the pool ... maybe not, we still have Tonga, we are only halfway, I don't want to get too far ahead.

"It's going to be a tough quarter-final no matter who we play. We can't control that, destiny will decide."

Watch live coverage of Ireland v South Africa (Saturday 23 September) on RTÉ2 and RTÉ Player, listen on RTÉ Radio 1 or follow our live blogs on RTÉ Sport Online and the RTÉ News app.