Joe Hancott, Bradley Lethbridge, both 18, and Leon Maloney, 17, are set to sign new one-year deals at Fratton Park.
It’s reward for their consistency during their two years playing for the Blues’ Academy.
All three have made their first-team debuts under Kenny Jackett.
Hancott became the club’s youngest player aged 16 years and 161 days in Pompey’s 3-1 Checkatrade Trophy victory over Fulham under-21s in August 2017.
After battling back from a broken foot at the start of this campaign, the Isle of Wight defender has been a regular in Mark Kelly’s side.
Lethbridge, meanwhile, made two starts during the Blues’ run to Checkatrade Trophy glory this season, coming against Arsenal under-21s and Southend.
The Gosport striker spent the majority of the campaign on loan at Bognor, scoring 12 goals in 38 appearances.
Maloney also came off the bench in the 2-0 third-round Checkatrade Trophy win at Southend.
The Isle of Wight forward netted 26 times for the Academy this term, while he’s spent the past few weeks at Nyewood Lane.
The trio will remain under Kelly’s wing for the 2019-20 season during a transitional period.
The Blues’ youth boss said: ‘They’re on third-year scholarships which is a transitional year.
‘It means they stay under the Academy’s control and we take them through that transitional year.
‘The nice thing about third-year scholarships is we can get them out on work-experience loans and can call them straight back for Checkatrade Trophy and under-23s games.
‘When they’re young pros then you get a problem so that's how we manage it.
‘We’re happy with that because they stay under our wing during the transitional time because they’re not going to jump into the first team straight away.
‘The three of them have been consistent over the year. Joe Hancott broke his foot at the beginning of the season but has been very consistent since coming back.
‘Leon Maloney has scored 26 goals. He’s quick and has raw attributes but now has got to develop into his body.
‘Bradley Lethbridge has things he has to develop – mentally and physically.
‘Everyone looks at him and thinks he’s a big boy but has a lot of growth in a lot of areas.
‘But all three have been consistent and it’s the next step for them.’
Meanwhile, Joe Dandy and Josh Flint will return to Pompey for pre-season in the summer as the final phase of their rehabilitation before departing.
Both have been out with long-term injuries.
And it means the end of Freddie Read, Oscar Johnston and James Whiting’s Fratton Park journeys.
Read made two appearances in the Checkatrade Trophy against Arsenal under-21s and Southend.
Johnston was named on the bench against the Gunners, while Whiting skippered the young Blues on several occasions.