Goals from JP McGovern and Kenwyne Jones gave Paul Sturrock's men victory four weeks just after Christmas and the Irish Under-19 star, fresh back from a victorious week with his international team, says Martin Foyle's men will come out all guns blazing.
O'Brien, who helped the Irish win 2-0 in Italy told Footymad: "Vale will be wanting revenge because we went down to their place and beat them 2-0 but they seem to be a good team as they had a few chances down there but it will be a good game. We (Ireland Under-19) played Italy on Tuesday and I was back on Wednesday to get ready for the game so hopefully I will be selected."
With Wednesday's international contingent now consisting of O'Brien, Glenn Whelan, Chris Brunt, Patrick Collins and now James Quinn - the spirit is good going into tonight's televised game and the only changes to the team are expected to be Quinn coming in for the newly-departed Jones in attack.
But as O'Brien continually impresses in the Owls engine room, he is playing an integral part of the Irish squad and playing teams of high quality.
He said: "The standard is pretty good. We qualified for the second phase of the European Championships so we are just playing friendly games at the moment. In the first stage we beat Russia which was massive for us but all the games we play are just preparation for the next stage."