Orr is struggling with an Achilles problem while Olsson has complained of tightness in his groin, both conditions could keep the players out of the starting line up in Wales, but manager Steve Kean is confident that both will be available.
Striker Anthony Modeste is available again after winning an appeal against the length of his ban.
Blackburn (from): Robinson, Orr, Dann, Hanley, Martin Olsson, Lowe, Nzonzi, Pedersen, Hoilett, Dunn, Yakubu, Kean, Bunn, Givet, Formica, Petrovic, Rochina, Marcus Olsson, Goodwillie, Vukcevic, Henley, Modeste.