There are four uncapped players in the 12 man squad - Llandovery wing Ifan Evans, back row forwards Michael Collins (Ospreys) and Jevon Groves (Cross Keys), amd Coventry scrum half Tom Slater, while Pontypridd's Gavin Dacey, also uncapped, will travel as a reserve player.
Northampton three quarter Will Harries, who is currently in impressive form on loan for Bedford in the First Division, performed well for Wales Sevens at the end of last season, and Ebbw Vale's James Lewis returns after being a permanent member of the squad last season. Jimmy Norris participated in the Dubai, George and San Diego Sevens earlier this season, while Dan Flanagan is no stranger to international Sevens.
John said, "This will be a steep learning curve for a number of these players. The majority of our World Cup winning side are unavailable to us which means we don't have the consistency of selection some other nations will enjoy. However, our continued aim is to help develop players into better professional rugby players and the current situation gives the whole squad the opportunity to do that in one of the IRB's most prestigious rugby events.
"Hong Hong is a 24-team tournament over three days, similar to the World Cup which means that only the top team in each Pool is guaranteed a path to the quarter-finals. We have China on the opening night, who will pose a very physical threat, then Japan and England on Day Two. Japan caused us problems when we faced them in San Diego recently, while England will be eager to prove a point after failing to qualify for the Rugby World Cup quarter-finals.
"We were able to take the same side on two tournaments - Wellington and the Rugby World Cup - and the results reflected that selection policy. We are not in the same position ahead of this tournament but the boys have trained well all week and I'm sure when it comes to selecting the squad for Twickenham and Edinburgh, these players will again be pushing for places."
Joe Lydon, WRU Head of Rugby Performance and Development, has wished the Wales Sevens squad well in their bid to build on the achievement of winning the Rugby World Cup Sevens by performing well at the Hong Kong tournament.
Only three players from the squad which lifted the Rugby World Cup Sevens trophy are included in the team which has been announced today.
Joe Lydon said: "Sevens has proved to be a breeding ground for talent across the world game and we are fortunate in Wales to have players of the calibre who can step in and perform at this level.
"There is a powerful argument for rotation in order to maximise player development in the Sevens environment, but we cannot ignore the importance of continuity which aids both development and performance in any selected squad.
"Many of the players who worked so hard to win the title for Wales would have liked to step back onto the international stage in Hong Kong. However, I am aware of the reasons this is not possible at such a crucial stage of the season for Regions and clubs alike.
"We fully understand the competition demands of the clubs and Regions and accept the current situation was inevitable but a formal agreement on player release for international Sevens is essential going forward.
"The WRU has already recognised this issue and we are working towards addressing player release, in partnership with our clubs and Regions."
Wales Sevens squad for Hong Kong and Adelaide Sevens:
James Merriman (capt, unattached), Tal Selley (Dragons), Rhys Webb (Ospreys), Ifan Evans (Llandovery), Jimmy Norris (Bedwas), Tom Slater (Coventry), Will Harries (Northampton), Dai Flanagan (Cardiff Blues), James Lewis (Ebbw Vale), Rhys Shellard (Cardiff), Jevon Groves (Cross Keys), Michael Collins (Ospreys), Gavin Dacey (Pontypridd)