Experienced midfielder Dunn has been troubled by a persistent calf problems since October, while widemen Nunes and Olsson are back from hamstring injuries.
Josh King is unlikely to be risked in attack as he continues his rehabilitation from a similar complaint.
Midfielder Dickson Etuhu (knee) and right-back Adam Henley (hamstring) remain on the sidelines along with long-term knee injury-victim Leon Best.
Rovers suffered their first defeat in five matches when Appleton began his tenure with a 2-1 defeat on Saturday - their sixth loss in the league at Ewood Park this season.
Brighton were scheduled to face Blackburn on December 22 but the match was postponed due to a waterlogged pitch.
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