With a 2-1 first leg advantage, Shelbourne will start as clear favourites ahead of tomorrow's Champions League, first qualifying round, second leg match with Glentoran at Tolka Park.
The winners will progress through to a second qualifying round tie against former European Cup winners Steaua Bucharest.
Captain Owen Heary admitted his team-mates were left kicking themselves after failing to secure the margin he believes they deserved from the first leg in Belfast.
He said: "We will approach the game positively and there is no way we will just be sitting back on our lead waiting for Glentoran to come at us. We created an awful lot of chances last week and I don't think Glentoran really deserved to get their goal back."
The Dubliner added: "Everyone will expect us to win and we will remember the positives of last week, because it is always difficult to go away and dominate a team for 80 minutes like we did."
Glentoran boss Roy Coyle is determined his side will seize upon Sean Ward's late lifeline last week to progress.
Coyle said: "Had it stayed at 2-0 it would have been a mountain to climb but we finished very, very strongly and that gave me great encouragement. We know the size of task ahead and we know we can improve."
