Both midfielders missed Saturday's SPL win against Kilmarnock, Brown with his troublesome ankle problem and Maloney with a recurrence of tendonitis in his Achilles.
Celtic must win in Germany if they are to maintain any real hope of qualifying from Group C.
Speaking at Glasgow Airport prior to the team's departure, Hoops assistant manager Mark Venus revealed Paddy McCourt was likely to replace Maloney in the squad.
"With Shaun out, we're a winger down, so I would imagine he'll be in among the 18-man list for the game," said Venus. "It's good that players are coming through and the gaffer's trusting them to play.
"With Marc-Antoine Fortune back too, we have an extra striker, so that gives us more selection problems."
Venus admits Thursday's game is a all but win-or-bust for Tony Mowbray's men.
"If we don't win, it's going to be very difficult for us to progress," he said.
"But looking at the game against them in Glasgow, we deserved to score, so I don't think it's an impossible task to go there and win the game."
Celtic (from): Zaluska, Hinkel, Caldwell, McManus, Loovens, Daniel Fox, McGeady, Crosas, N'Guemo, McCourt, McGinn, McDonald, Fortune, Samaras, Naylor, Wilson, Cervi, Robson, Thompson, Caddis.