Scarlets' Euro home advantage in jeopardy
According to the tournament rules, venues for the knockout stages must offer a minimum 15 000 capacity.
Scarlets' home, Parc y Scarlets, currently has a capacity which falls just shy of that at 14 870.
The Welsh side may have to install temporary seating for the quarterfinal or move to another stadium.
The Scarlets could move to the Liberty Stadium or the Millennium Stadium.
The Cardiff Blues faced Toulouse at the Millennium Stadium in 2009, beating the French team 9-6.
— Champions Cup (@ChampionsCup) January 21, 2018