Ospreys teenager Keelan Giles has been described as an "X factor" player after being called into Wales' autumn Test squad.

The 18-year-old uncapped wing replaces Hallam Amos, who suffered a shoulder injury during Wales' 32-8 capitulation to Australia three days ago and now faces probable surgery.

While Giles, who had been training alongside the squad as an additional player before Tuesday's development, appears unlikely to feature against Principality Stadium visitors Argentina next Saturday, a Test debut looks inevitable sooner, rather than later.

Giles starred for Wales Under-20s last season and he has scored eight tries in five Ospreys appearances this season, prompting many pundits to make comparisons with Wales' all-time record try scorer Shane Williams, given his blistering pace and dazzling footwork.

"We have got a lot of good players, a lot of good wingers," Wales skills coach Neil Jenkins said. "Keelan has got to take his chance with both hands and show the coaches and the players involved what he is all about. He has already done it with the Ospreys, and I am sure he will do that in our environment.

"He has got a little bit of X-factor about him. He is a different player to some of the other guys we've got. I know a lot of people will bring similarities with Shane (Williams) and stuff. Keelan is not the biggest of players, but he's electric on his feet and he is brave. We will see how the next couple of weeks go, and you never know."

Amos, who impressed when he went on as a second-half substitute last weekend, has been released back to his region Newport Gwent Dragons.

He has got a little bit of X-factor about him. He is a different player to some of the other guys we've got. <p>Neil Jenkins</p>

Wales' interim head coach Rob Howley is due to name his team for the Pumas' visit on Thursday, and there will be changes following Australia's demolition job. Gareth Davies is expected to replace injured scrum-half Rhys Webb, while skipper Sam Warburton, lock Alun Wyn Jones and centre Jonathan Davies should all be back in the mix, and Liam Williams will strengthen Howley's back-three options if he has regained full fitness.

The Wallabies inflicted a heaviest home defeat on Wales for 10 years, and Jenkins knows from some of his experiences as an international player just how bad the feeling is.

"It's what you dream of, representing your country, performing well and winning, but when things don't go to plan, it's not the best day and it does take quite a few days to get over it," he added. "Sport gives you a chance to go again, a chance to redeem yourself and put the wrongs right. I think a lot of us would liked to have played (again) on Saturday night if we could have done.

"It is hugely disappointing. You don't want to let yourself, your country, your team-mates, your family, your friends or the fans down. You give your all for your country. There is a big build-up to matches and there is a lot of pressure. When it doesn't go to plan, it's hugely disappointing."

Wales have beaten Argentina in four of the countries' last five meetings, but Jenkins knows their danger and has been impressed with how they have modified their game.

"After our performance on Saturday, they will certainly come here fancying their chances," he said. "It is up to us to make sure that we play like we can play, and if we can do that, we are more than capable of doing a job on Saturday and winning the game.