Rosser, 20, is one of the Guinness Pro14's biggest young prospects with the former Wales U20 wing enjoying a breakthrough season at the Dragons for Rosser playing 25 games and finishing the campaign with seven tries in seven games, including a hat-trick against Zebre.
Talbot-Davies, also 20, made his regional bow in 2016 but has stayed under the radar after spending much of last season with the Sevens.
Full Wales internationals Lloyd Williams and Cory Allen have also been selected by head coach Gareth Williams for the trip to America, whilst it is one last hurrah for captain Adam Thomas, Wales' stalwart who will be competing in the Principality Premiership next season.
Head Coach Bernard Jackman says the Dragons felt Rosser's inclusion was a win-win with benefits for the player, country and region
The hope is Rosser will use this competition to his benefit with preparation in the professional environment of the World Cup Sevens camp, playing in large stadium and under pressure giving the best development for the speedster, who can also use the tournament to hone his skills in finishing, beating defenders and the contact area.
"We feel this was a good way of dealing with his summer to accelerate his development and gives Jared a mental break whilst playing in a high level competition," said Jackman.
"It also gives us a chance to look at some new players and I’d include George Gasson as new as well plus Dafydd Howells and Jordan Williams are now with us."
Sevens Head coach Gareth Williams said: "This is a great culmination to our season. The World Cup has been an aim of ours for the past 18 months and we're excited with the squad we have put together.
"We are building nicely towards the opening match versus Zimbabwe, and starting well against their physicality and elusiveness is a key aim of ours.
"The tournament structure is different, but exciting, and we are eager to get out there and get things started."
Wales will face Zimbabwe in the 'pre-round of 16' matches at 22:00 BST this Friday, with the knockout format significantly increasing the stakes in this year's tournament. The Rugby World Cup Sevens will take place at AT&T Park, the home of baseball's famous San Francisco Giants, and will be broadcast on ITV.
Wales Sevens: Luke Treharne, Ethan Davies, Lloyd Williams, Luke Morgan, Owen Jenkins, Tom Williams, Cory Allen, Afon Bagshaw, Adam Thomas, Cai Devine, Jared Rosser, Ben Roach, Will Talbot-Davies.
WC Sevens record:
1993 – Plate SFs
1997 – Plate QFs
2001 – Plate SFs
2009 – Champions
2013 – Cup QFs
2018 seeding: 12
