We look at Pompey's form on their return to third tier, past encounters, the player to look out for and at the man at the helm...
A steady start...
Having pipped Plymouth Argyle and Doncaster Rovers to the League Two title on the final day of last season in dramatic fashion, Portsmouth have made a steady start to their League One campaign.
Kenny Jackett's men currently sit 15th in the division, having won four, drawn two and lost five.
Inconsistency appears to be a problem of late with the side following a win then lose pattern for the past seven games.
Pompey head into tonight's game off the back of a 2-1 defeat to Oldham Athletic, who had only won twice prior to Saturday's result.
They are third in the EFL Trophy Southern Group A, having lost on penalties to Fulham U23s at Fratton Park last month.
First time for everything...
The Reds have met Portsmouth on six occassions since 2012, losing four, drawing one and claiming just one victory.
All of those encounters have come in the league, meaning tonight's game will be the first cup game between the two.
Crawley's solitary win came on Boxing Day in 2012 at Fratton Park, in a League One clash that finished 2-1.
The hosts had taken the lead just 11 minutes in, but an equaliser from Nicky Adams and a 73rd minute winner from Billy Clarke completed a comeback for the Reds.
Mark Connolly played the full 90 minutes that day.
Keep an eye on...
Despite being just 20 years of age, Chaplin has been involved in the first team set up at Portsmouth since 2014.
The young striker could make his 100th appearance for the club tomorrow, an impressive stat for someone of Chaplin's age.
Although predominantly coming off the bench, the hot prospect has featured 10 times this season, scoring twice.
He was used as a second half substitute in Pompey's first Checkatrade Trophy game of the season, against Fulham under-23s.
Kenny Jacket was appointed as Paul Cook's successor ahead of the current season, in what is his sixth managerial job.
The former Wales international started his career in management at Watford; the club he spent his entire playing career and placed himself in sixth in the club's all time appearance records, pulling the Hornets shirt on 428 times.
It could've been more if Jackett hadn't been forced to cut his career short to 10 years in 1990 due to injury problems.
He was appointed manager of Watford in 1996 after working as a coach for the club following his retirement from playing.
The 62-year old only remained at the helm at Vicarage Road for a year with Graham Taylor returning to his management role after he had been the Director of Football.
Jackett then reassumed his coaching role before leaving permanently in 2001, and joining QPR as assistant to Ian Holloway where he remained for three years.
In 2004, he took over at Swansea City, and achieved promotion from League Two and lifted The Football League Trophy before moving on to Millwall in 2007.
Jackett's longest managerial stint was at The Den, where he was in charge for six years and gained promotion the Championship via the 2009/10 play-offs.
after an impressive following season in the second tier, finishing 9th, Millwall then struggled the two seasons after, however survived on both occassions before resigning from his post in 2013 to pursue a new challenge.
Jackett had a short spell at Rotherham that lasted just 39 days, before joining current club Portsmouth in June.
Click here for information on tickets for the game this evening - it's pay on the gate for Reds fans.