The Dragons failed to qualify for the Heineken Cup this season, but have impressed in Europe in the second tier ChallengeCup competition and are going well in the Magners League.
However, even if the Scarlets lose to Cardiff Blues on Saturday they could still qualify if the Blues win the Amlin ChallengeCup as Europe's second-tier tournament offers a Heineken Cup place next season for the competition winners.
Pontypridd are the only other Welsh side to qualify for the ChallengeCup final - Europe's second-tier tournament - which they lost to Sale 25-22 in 2002.