Luxembourg is described as a "strong Quidditch nation" (QA8). As it is such a small country, however, the Bigonville Bombers Quidditch team may possibly provide many of the players for Luxembourg's National Team.
Lexicon list of European Quidditch Teams
From the Web
Writing by J K Rowling on WizardingWorld.com (Pottermore): Wizarding Schools
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Harry Potter Wiki: Quidditch