The Blues romped into the final with three victories in the Welsh leg of the competition at the BT Sport Cardiff Arms Park last month.
But they will be without a host of their young stars who are now with Wales Under-18s and depart for South Africa early next week.
Richard Hodges has bolstered his squad with Ethan Davies, who joins fellow Wales 7s core members Adam Thomas, Ben Roach and Owen Jenkins.
Ceri Young, who was player of the tournament in the recent Cardiff and District 7s adds to the region’s wing options.
Academy prospect Morgan Sienawski replaces James Botham, while there are also places for invitational stars Johnny Lewis and Aron Wyn Evans.
Hodges will once again lead the squad and is joined by skills coach Paul John, who has an abundance of experience from Wales 7s. Rugby General Manager Billy Millard will act as team manager on the day in Coventry, bringing his five years’ experience as Australia 7s head coach.
Cardiff Blues 7s squad: Adam Thomas (capt), Ben Roach, Morgan Sienawski, Luke Crocker, Joe Tomlinson, Ceri Young, Owen Jenkins, James Beale, Johnny Lewis, Ethan Davies, Aron Wyn Evans, – Declan Williams.
