They head back into continental competition at Rodney Parade on Friday, December 6 knowing that back-to-back wins would keep them hot on the tails of group leaders Bath ahead of their Round Five meeting with the West Country men in Newport at the start of the year.
But they won't be able to call on the services of wing Tom Prydie and scrum-half Jonathan Evans after the duo suffered injury setbacks last week.
Prydie, who is one of the Dragons' front-line goal kickers, pulled up with a hamstring injury while training with Wales on Tuesday, while Evans picked up a shoulder problem during the LV= Cup win over London Wasps on Saturday.
A try scorer in the seven-try thrashing of Rugby Mogliano in Round One of the Amlin Challenge Cup, Evans was forced out of the 20-8 Anglo-Welsh victory and is expected to be sidelined for between four to six weeks.
Prydie faces the same length of absence, meaning that, as well as missing the European encounters and the domestic clashes with Glasgow Warriors and Munster, he won't be able to feature for his country in the remaining two autumn internationals.
"Tom has been in good form this season and was growing in confidence and it's disappointing that he picked up an injury because I am sure he would have been in line for selection for Wales against Tonga," said Dragons boss Lyn Jones.
"It's a shame because Tom was just getting his game back together and was starting to build. He's had a tough couple of years since being selected for Wales (he won the first of his five caps as an 18-year-old three seasons ago), that was maybe before he was ready and he struggled to live up to that."
The Dragons will hope that both Prydie and Evans will be back fit in time for the home tie with Bath on the weekend of January 9/10/11/12 as they look for a first European quarter-final spot since the 2006/07 season.
That penultimate pool fixture is seven-and-a-half weeks' away, leaving the pair with little room for error if they are to return to top form for what could prove to be a pool decider.