(Reuters) -Coach Steve Tandy has called centre Joe Roberts and uncapped tighthead prop Ben Warren to his Wales squad ahead of their final two games of Autumn International series against New Zealand and world champions South Africa.

There was sweet relief for new coach Tandy when a late Jarrod Evans penalty lifted the side to a 24-23 victory over Japan in Cardiff on Saturday.

But the challenge will rise several notches over the next two weeks, leading to the call-ups for Roberts and Warren, both 25, especially as Tandy will be without 13 players for the Springboks game, which falls outside the international window.

"We have decided to add Joe and Ben to the squad this week as an important part of our preparation for the final two weeks of our autumn campaign," Tandy said.

Wales host New Zealand on Saturday and the Springboks on November 29.

(Reporting by Nick SaidEditing by Christian Radnedge)