The hosts sit 18th in the fourth tier whilst the visitors are rock-bottom, five points behind the Exiles.
Match preview
These two teams have met three times previously in the competition, Newport's sole victory coming in the 1969-70 season, with Colchester eliminating the Welsh side in the 1978-79 and 1981-82 seasons.
Will Evans's seventh-minute header was the difference between the sides in their latest encounter in the league, securing the win in Exiles manager Graham Coughlan's first game in charge.
The former Bristol Rovers and Mansfield Town boss has arrested a run of three defeats following victory over the U's in his debut with draws away to his former club The Stags and promotion-chasing Northampton Town.
The Port have an increasingly impressive recent history in this competition, winning 15 FA Cup games since they returned to the Football League in the 2013-14 season - more than any other League Two club in that timeframe.
Their only home defeat in the competition in their last 11 such games came against Manchester City in the fifth round in 2019, with eight victories and two draws in that time.
On the other hand, Colchester have lost six of their last eight away matches in the tournament, the only win coming against non-league AFC Sudbury in the first round in November 2021.
The U's are without a win in their last six matches in all competitions, a 3-1 defeat to high-flying Barrow on Tuesday night becoming the latest result in that poor run.
Manager Matt Bloomfield insists he is the right man to turn fortunes around at the Jobserve Community Stadium, despite the fact that he has just one win to his name since taking over from Wayne Brown in September, in his first managerial role.
Newport County form (all competitions):
L
L
W
W
D
D
Colchester United form (all competitions):
L
L
L
D
D
L
Team News
Graham Coughlan is considering shuffling the pack after picking the same starting XI in his first three matches in charge so far.
The only confirmed absentee for the hosts is striker Offrande Zanzala, who is ruled out with a hamstring injury.
For the visitors, they are without Cole Skuse, Kwesi Appiah, John Akinde and Matty Longstaff, whilst Tommy Smith and Clay Cooper are long-term absentees.
Midfielder Emyr Huws is back in first-team training but the clash is expected to come too soon for the former Ipswich man. Meanwhile, Tom Dallison missed the defeat against Barrow and remains a doubt.
Newport County possible starting lineup:
Day; Clarke, Dolan, Demetriou; Norman, Wilmott, Bennett, Waite, Lewis; Evans, Bogle
Colchester United possible starting lineup:
Hornby; Tchamadeu, Chambers, Eastman, Clampin; Hannant, Judge, Marshall-Miranda, Kazeem, Newby; Sears