The 24-year-old, who is currently recovering from a knee injury picked up last month, had featured 27 times in League One for Pompey this season, with 16 of those coming in the form of starts.
Hackett-Fairchild netted four times and assisted a further two in his 27 appearances for the League One outfit this season, primarily operating as a left wing-back.
Proving to be a versatile option for Danny Cowley to have in his squad, the young winger has also been deployed higher up the pitch in wing positions, a number 10, and as a striker.
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Arriving in January 2020 from Bromley, Hackett-Fairchild is enjoying his first season of seeing regular minutes within the EFL.
Proving to be a real attacking threat, whilst developing from a defensive perspective, Hackett-Fairchild has looked an excellent option at left wing-back at times this season.
His ability to get past a man, coupled with his final third contributions, have seen him emerge as a dangerous asset for Cowley to have within the squad.
Given that he is out of contract and is currently recovering from injury, Pompey could have quite easily opted to part company with him, with this decision showing the faith that the club have in him.
It remains to be seen how long the recovery will take and whether he will be ready to go for the start of pre-season, but the ceiling remains to be high with Hackett-Fairchild, which further justifies this decision to submit a new contract offer.