Derek Adams believes Plymouth share ‘a lot of similarities’ with their Pompey hosts.
The Pilgrims venture to Fratton Park tomorrow for what promises to be a fascinating encounter.
The televised occasion pitches second against third in League Two as the promotion battle steps up in intensity.
There is little love lost between either dressing room, while Plymouth eliminated their opponents from the play-offs last term.
It has developed into a genuine modern-day rivalry between the two talented sides.
And Adams insists the clubs are comparable.
Adams told the Plymouth Herald: ‘Portsmouth are trying to gain automatic promotion, as we are. We are both in a similar situation.
‘We have both been able to put ourselves in a good place and they will be looking to win the game, as we are.
‘I think that the rivalry has been good. The clubs are of a similar nature.
‘Portsmouth have been in the Premier League and been in administration twice. Plymouth have been in the Championship and been in administration once.
‘There are a lot of similarities. Both cities have got dockyards and both are well-supported teams.
‘The pitch is in fabulous condition and the players can pass the ball on it, unlike against Crawley where it became very difficult.
‘It is a terrific atmosphere (at Fratton Park). Their home supporters give them tremendous backing.
‘We will have 2,500 away supporters and they will give us outstanding backing, as they did against Crawley.
‘We know what a win would mean to them.’
The sides shared a 2-2 Home Park drew earlier in the season, following Connor Smith’s 89th-minute equaliser for the hosts.
Last term it was a win apiece, with each arriving in the opposition’s camp.
Crucially, however, the Pilgrims emerged triumphant through the two-legged League Two play-offs.
Peter Hartley’s last-gasp goal settled the fixture 3-2 in favour of Adams’ men, who went on to lose in the final against AFC Wimbledon.
It was a crippling blow to Pompey, yet boss Paul Cook afterwards entered the Plymouth dressing room to deliver his congratulations.
Regardless, the managers have a fractured relationship borne out of encounters during the last two seasons.
Although, ahead of tomorrow’s game, Adams has played it down.
He added: ‘We get on fine.
‘We are managers of very big football clubs and the will to win is there from both of us. I think that’s important.’