Both sides are unbeaten in Group Eight but a greater number of draws have cost the Republic dear and Giovanni Trapattoni's men trail the Italians by four points heading into the penultimate round of qualifiers.
A point will secure Marcello Lippi's side qualification to the finals while the Republic need to pick up two points from their final qualifiers if they are to be assured a place in the play-offs, with Bulgaria still in with a shout.
The Italy camp is under something of a shadow on the eve of the match after it emerged skipper Fabio Cannavaro failed a drug test after taking a medicine that contained the banned substance cortisone.
Cannavaro's club, Juventus, have claimed the defender needed cortisone treatment for an insect sting in August, but the incident is not expected to prevent him joining with the Italy squad in Coverciano on Sunday as planned.
Cannavaro was interviewed by the Italian Olympic Committee's anti-doping prosecutor in Turin yesterday but Lippi does not expect his star to be absent from the squad.
"I have not spoken to Cannavaro," said Lippi. "But there was no need.
"Will he be here with us on Sunday? Of course he will."
Cannavaro would not have featured in Dublin as he serves a one-match ban, but is expected to lead the Azzurri in their final qualifier against Cyprus in Parma on Wednesday.
Things are less fraught in the Republic camp and winger Aiden McGeady is in upbeat mood ahead of tomorrow's encounter.
"If we win, the group is wide open and even a draw almost guarantees us second place in the group," the Celtic star said. "But it's a game we want to win, especially because we are at home.
"So far, we're unbeaten in the group and a win would be unbelievable.
"Italy are still world champions and it's going to be tough, but we're all looking forward to the challenge.
"Reaching a World Cup would be unbelievable. Growing up, it's something you dream of.
"You want to test yourself against the best players on the biggest stage and hopefully that dream can come true for me."
Elsewhere in the group, already-eliminated Cyprus play host to a Bulgarian side still with an outside chance of pipping the Republic to second place and a play-off berth.
The third-placed Bulgarians have only suffered one loss in eight qualifiers but five draws - including frustrating stalemates against both Georgia and Montenegro - have left them trailing Trapattoni's men by five points with two matches remaining.
Tomorrow's remaining Group Eight encounter sees two winless sides, Montenegro and Georgia, do battle in Podgorica as both try to avoid the ignominy of finishing bottom of the pile.