Cardiff Blues wing Harry Robinson, part of Warren Gatland's RBS 6 Nations training squad and the Wales Sevens squad, is joined by four-cap international Tom Prydie and impressive Ospreys flyer Eli Walker.
Centres Jack Dixon, of Dragons, and Ospreys Matthew Morgan are also included, along with Tom Habberfield with Wilson insisting the added experience will benefit his charges in South Africa.
"The players who have joined the squad since the Six Nations have already brought a new intensity to our training sessions and we hope that their regional and international experience will help lift our playing performances too," he said.
"The additional players have certainly improved our strength in depth, but now we must have a good month training in order to get on the plane feeling well prepared."
Wales play Fiji, New Zealand and Samoa in Pool A of the tournament - a group that will certainly test the Welsh youngsters, according to Wilson.
"It is an extremely physical group and we must meet that challenge head on if we want any chance of progressing to the top half of the draw," he said.
"New Zealand have proved year after year that they are the strongest side in the world at this age, so they will again be a huge challenge, but we must target our other Pool games against Fiji and Samoa.
"We saw last season that those sides are very dangerous and we must execute the right game plan against them. We must be physically and mentally ready for all three games."