Wales are following the Ospreys’ lead in showing a cautious approach to teenage wing Keelan Giles, according to Rob Howley.

Despite a clamour for Giles to be given a start against Japan on Saturday – the easiest of the four autumn Tests – the 18-year-old dubbed as the new Shane Williams will be on the replacements’ bench.

The decision not to give the pacey Wales U20 star a place in the starting line-up contrasts with Cory Hill, the Newport Gwent Dragons lock who will make his first start for his country alongside Alun Wyn Jones.

Howley said: “The Ospreys and (head coach) Steve Tandy have been particularly impressive in how they have developed a young talent. It is important we continue that on the international scene.

“Hopefully, he will have an opportunity to come on, on the wing in an experienced back three, so he can enjoy his first touch of the ball in international rugby.”

Giles has scored eight tries in five games for the Ospreys this season, but had to wait until October 14 for his first regional start against Newcastle Falcons.

If he is capped this weekend, Giles will become Wales’ 11th youngest senior international but Howley has urged fans to tread as carefully as he is.

“Give him time,” he said. ” Don’t give him as many headlines as he has had over the last couple of weeks.”

Howley has made 10 changes to the starting XV following last weekend’s solid 24-20 victory over Argentina.

The switches include a recall for centre Jamie Roberts, who was dropped to the bench against the Pumas, and opportunities for the likes of Cardiff Blues half-backs Gareth Anscombe and Lloyd Williams, Ospreys prop Nicky Smith as well as Hill.

The 24-year-old former Cardiff Blues forward was added to the Wales squad after impressing in training following a call-up to cover for injuries and made a surprise international debut off the bench in the 32-8 loss to Australia.

Hill was an unused replacement in last week’s win against Argentina but gets the nod for the Brave Blossoms.

“He’s calling the lineouts so there is a responsibility in that department in getting our set piece right,” said Howley.

“The old adage is the forwards decide who wins the game and the backs decide by how many and I was really pleased with our set piece against Argentina.

“Cory has added value in that department over the last couple of weeks and has certainly been a find for us, there’s no doubt about that.

“We are looking forward to his first game and to play alongside one of the world’s best locks, what a story to tell in future years.

“We are looking forward to what Cory can bring individually and collectively in adding to our pack.”

Liam Williams and Leigh Halfpenny, meanwhile, swap positions with Williams moving to full-back and Halfpenny on the wing, with flanker Sam Warburton captaining the team.

“It is an opportunity for some of the players to put their hands up after a disappointing performance against Australia,” Howley added.

“There is also a chance to blood some new players with experienced players around them like Cory Hill alongside Alun Wyn Jones, James King alongside Dan Lydiate and Sam Warburton, and Keelan and Sam (Davies) coming on in an experienced back line.

“We are playing Liam in his preferred 15 role. I feel it is the best three to play in the back three against Japan. It is as simple as that.

“It is about seeing the combination of Leigh and Liam playing together. George (North) has played the last two games and, as I have said, it is important we give everyone an opportunity to put their hand up for next week.”

Wales include three starting line-up survivors from the side beaten by Japan in Tokyo three years ago – Liam Williams, Lloyd Williams and back-row forward James King – but the countries’ four previous Cardiff encounters saw Wales post a total of 289 points.

“They (Japan) had a really good win against Georgia last weekend (28-22 in Tbilisi),” Howley said. “The tries they scored in that game sums up Japan over the last couple of years.

“They play a high-octane game. They are a great counter-attacking side, and we have to be on our mettle.”