Long-term absentees striker Farid El-Alagui (knee) and midfielder Kevin O'Connor (ankle) are the only players missing as the Bees look to pull off a major cup shock.
The Bees were seven minutes away from knocking out the European Champions in the original tie and Rosler feels as though his side's best chance of progressing has passed them by.
He told the Fulham Chronicle: "The surprise factor has gone. We had the chance to beat them because they underestimated us the first time around, but they won't do that again.
"They will take us more seriously this time around."
Toumani Diagouraga and Marcello Trotta are expected to return after starting on the bench during the 2-0 win over Stevenage in midweek.