Andrew Cullen has backed Danny Cowley to build a Pompey squad that suits his style of play.
Several players have departed since the end of last season, with teenage full-back Liam Vincent the only arrival so far.
But there is still just under two months until the 2021/22 League One campaign starts, with training not beginning until the end of June.
And Cullen insists that the Blues will take their time to ensure they get their recruitment right this summer.
Pompey’s chief executive said: “Danny has a very clear vision of how he wants this team to play and will recruit the players that best fit that model.
“We have to give him the space to do that – and it’s not necessarily something that’s going to happen across one window.
“The process starts with players who are out of contract and then you start to look forwards to recruitment.
“I think we’re looking at people with potential who can become assets for Portsmouth Football Club, but also fit exactly what Danny wants to do.
“It’s a long window and we have to be patient. There’s some business being done by clubs at the moment, but not a lot.
“We want to be very smart about how we recruit players and that’s something that’s one of the priorities for me.”
"It’s a long window and we have to be patient. There’s some business being done by clubs at the moment, but not a lot."
Cullen has underlined the importance of the Fratton Park redevelopment work that recently got underway.
He said: “It’s an old stadium that constantly has to be improved to fit in all the necessary requirements.
“That’s important because supporters need to know that when they visit Fratton Park, their safety is paramount.
“So we have to make those improvements and it gives us a chance of looking at what we want to do in all four stands.
“If we’re going to get into the Championship then we have to make sure we’re ready or those capacity cuts will get stronger.
“You can’t do everything at once and we’ve just gone through the most unreal times because of the pandemic.
“But the commitment from Michael and his family to fund £10 million – on top of what they’ve had to fund due to the losses from Covid – is tremendous testament to their commitment to the club.
“We’ll get this first stage done, see where the club goes and what the optimum capacity for the stadium is.
“You want to constantly be looking at getting that right, including the hospitality and commercial opportunities that might come.
“All of these things can produce money that can be reinvested into the team, so you want that return in investment.”