Kenny Jackett revealed safeguarding Jack Whatmough’s availability was behind his surprise Accrington omission.
The central defender’s run of six-successive League One starts was halted at the Crown Ground on Saturday, with Christian Burgess recalled.
Burgess was among four changes as the Blues claimed a 1-1 draw against John Coleman’s side, ensuring their lead at the top of the table was cut to two points.
Whatmough’s dropping to the bench was an intriguing team selection by Pompey’s boss following the midweek 2-2 draw with Burton.
And Jackett admitted the decision centred on protecting the youngster from any potential injury recurrence.
He said: ‘There was no injury to Jack.
‘I felt sometimes he looked a little bit leggy after the third game in a week and, with the injury history that he's had, I want to make sure we give him every chance and protect him because he has been a big player for us this season.
‘You just look at your players and assess them. I looked at him Tuesday and through the week and he’s a very good player and a key player for us and didn’t think it was the wrong thing to do –instead I put some fresh legs there against (Offrande) Zanzalas’s pace.
‘As it goes on and he gets more of a run then that (playing three games in a week) will be better. Obviously he’s had one niggling groin injury this season which didn’t keep him out too long and his availability has been good.
‘For a player who has so much talent, we want to keep him and give him every chance to be as fit and available for as many games as possible.’
Whatmough missed four matches with a groin problem last month, before returning to the side.
Jackett’s interest in protecting the Gosport youngster ensured the resumption of the Matt Clarke/Burgess defensive axis which has served Pompey so well since the summer of 2015.
Burgess responded with a powerful defensive performance against an Accrington side positioned fourth before kick-off.
The former Peterborough man has found himself behind Whatmough for first-team selection since the final third of last season.
Jackett, however, had no qualms bringing back a player who has amassed 136 appearances and seven goals since arriving at Fratton Park under Paul Cook.
With a trip to Bradford next on the agenda, it will be interesting whether Burgess will now keep a fully-rested Whatmough out of the starting XI.
Jackett added: ‘Christian came in with his experience and also Zanzala is pretty strong in that channel. He didn't let us down at all.
‘Clarke and Burgess have been a good partnership for Portsmouth for a number of years.
‘It’s just probably in recent times Jack has just edged him out, but Christian is a good player and I’m very confident in him.’