Mesut Ozil, Olivier Giroud, Mathieu Debuchy and David Ospina are all sidelined, while goalkeeper Wojciech Szczesny is suspended after picking up a red card against Galatasaray, so third-choice stopper Emiliano Martinez is expected to make his Champions League debut in Belgium.
The North London outfit were held to a 2-2 home draw by Hull City on Saturday, but Flamini believes that the team can have no excuses.
"We're having injuries but we don't want to hide behind any excuses," the Frenchman told The Guardian.
"We're facing the truth – we didn't win on Saturday and we'll try to find a solution for the next games."
Arsenal beat Galatasaray 4-1 at the Emirates Stadium in their last group stage match.