Sweeney crosses for try against former club Boxing Day 2008
Huw Evans PA
Dragons Coach Paul Turner confirms fly half Jason Tovey and lock Luke Charteris fail late fitness tests, but centre Ashley Smith returns.
Joe Bearman, Grant Webb, Aled Brew, Pat Palmer and Matthew Watkins are also out. Those injured Dragons players join lock Adam Jones and flanker Dan Lydiate - who are out for the season - plus Danny Lee on the sidelines.
James Arlidge starts at outside-half as Tovey has failed to recover from a knock sustained in last weekend's win over Edinburgh. Bearman is replaced in the back-row by Newport RFC captain Andrew Coombs.
"I'm really hoping it's going to be a high energy game with a lot of movement of the ball and two teams trying to take each other on," said Dragons backs coach Darren Edwards.
"They've got quality players that we will have to stop and to do that, we will have to be in their faces. We are developing a style of play and it is attack."
Newport Gwent Dragons: Martyn Thomas; Will Harries, Tom Riley, Ashley Smith, Richard Fussell; James Arlidge, Wayne Evans; Hugh Gustafson, Tom Willis (capt), Ben Castle, Rob Sidoli, Hoani MacDonald, Andrew Coombs, Gavin Thomas, Toby Faletau.
Replacements: Lloyd Burns, Nigel Hall, Lewis Evans, James Harris, Rhodri Gomer Davies, Adam Hughes, Alex Walker.
Are you going to the big international this Friday night as Wales tackle France in the 6 Nations at the Millennium Stadium? If so, you can enjoy a double dose of top class action with our special deal to watch the Blues!
On Saturday, February 22 the Cardiff Blues Supporters' Club (CBSC) are hosting an informal event during which Josh Navidi will be presented with his Player of the Year Award for last season, as voted for by members of CBSC. Rhys Patchell will also be collecting his Newcomer of the Year award.
Cardiff Blues face back-to-back home games in the RaboDirect PRO12 as the region goes all out to secure a top six finish - and you can be part of the big match action under the floodlights at the Arms Park with tickets to both games on sale NOW!
A controversial disallowed injury time try from Harry Robinson saw Cardiff Blues leave Italy both disappointed and frustrated as Zebre claimed a tense 15-10 victory in the RaboDirect PRO12 clash at the Stadio XXV Aprile in Parma.