The teams reconvene at the Silverlake Stadium following a 1-1 draw in their opening encounter, and for the winner, a glamour fourth-round showdown with Manchester United awaits.
Match preview
FA Cup third-round appearances are not entirely novel to Tuesday's hosts Eastleigh - one of two non-league sides still battling for FA Cup glory alongside sixth-tier Maidstone United - as they got this far in back-to-back seasons in the 2015-16 and 2016-17 campaigns.
Bolton Wanderers and Brentford sent them packing on those two occasions - the former club coincidentally triumphed in a replay following a 1-1 draw in the opening encounter - but the soaring Spitfires now have every right to dream of a historic fourth-round appearance.
After following up a qualifying success over Dover Athletic by sinking Boreham Wood and crisis club Reading on home soil, Eastleigh somehow snatched a draw from the jaws of defeat at Rodney Parade on January 6, where James Clarke's opener was cancelled out by a Chris Maguire penalty.
The achievements of Richard Hill's side were even more commendable when noting that Eastleigh played the entire second 45 a man down - George Langston was banished from the field in the 38th minute - and they have only ever lost an FA Cup proper home match on penalties.
However, the Spitfires' tune-up match for Tuesday's replay on Saturday did not follow the script, as Southend United ran out 1-0 winners in their National League clash, condemning Eastleigh to a fourth successive game without a win across all competitions.
Unfortunately for Eastleigh, they must now renew hostilities with a Newport County side who boast enviable replay nous, having won each of their last four FA Cup rematches since going down to Tottenham Hotspur in such circumstances six years ago.
Prior to their opening stalemate with the Spitfires, Newport County were held to a 1-1 draw by Barnet in the second round before bringing their best shooting boots to the Hive Stadium in a 4-1 thrashing, thus reaching round three for the fifth time in seven seasons.
However, for all of Newport's recent replay endeavours, the Exiles have actually suffered four successive rematch defeats in the third round, and each of their last two appearances at this stage of the FA Cup have ended in defeat.
The form book favours Graham Coughlan's side, though, as while Eastleigh lost by a single goal at the weekend, Newport triumphed over Doncaster Rovers by a 1-0 scoreline in League Two action thanks to a Seb Palmer-Houlden effort in the third minute of second-half injury time.
A five-game unbeaten run could now become six for Newport should they end Eastleigh's FA Cup fantasy at the Silverlake Stadium, otherwise Man United will visit the Spitfires' humble surroundings rather than Rodney Parade at the end of the month.
Eastleigh FA Cup form:
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D
Eastleigh form (all competitions):
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L
Newport County FA Cup form:
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D
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D
Newport County form (all competitions):
L
W
D
D
D
W
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Team News
Just 12 minutes after first entering the referee's book, Eastleigh defender Langston was made to take the walk of shame for an elbow on Harry Charsley, although Hill was not convinced that referee Edward Duckworth made the right call.
With Langston's dismissal going down as a straight red card rather than a second yellow, the 21-year-old will not be eligible to take part in Tuesday's game, so Ludwig Francillette deputise in the hosts' back five.
Striker Scott Quigley only lasted until half time of the loss to Southend at the weekend, although the decision was seemingly a tactical one; opposition boss Kevin Maher felt that Quigley was fortunate to avoid being dismissed for a rash tackle on Cav Miley.
While Newport have no disciplinary concerns to factor in for the replay, the visitors lost centre-back Matthew Baker to an ankle injury with 15 minutes left to play against Doncaster, so a rearguard alteration could also be on the cards for Coughlan.
Nineteen-year-old defender Josh Seberry is already working his way back from a fibula fracture, while Declan Drysdale is recuperating from a hamstring injury, so full-back Lewis Payne might be pressed into a central role on Tuesday.
Eastleigh possible starting lineup:
McDonnell; Boldewijn, Croll, Francillette, Hodson, Clements; Atangana, Taylor, Maguire; McCallum, Quigley
Newport County possible starting lineup:
Townsend; Payne, Delaney, Clarke; McLoughlin, Bennett, Waite, Morris, Lewis; Evans, Palmer-Houlden
We say: Eastleigh 0-1 Newport County
Unwanted defensive changes would not have been on either manager's agenda this week, but with the motivation of hosting the Red Devils in the fourth round, neither teams need an additional incentive to extinguish their opponents' cup dreams.