Yet the ongoing development of rival Brandon Haunstrup continues to impress the Blues boss.
Brown was handed an instant recall at Doncaster last weekend following six weeks sidelined with an Achilles injury.
During that eight-game absence, Haunstrup seized ownership of the left-back role, producing a string of impressive displays.
That pitched the pair head-to-head upon Brown’s return, only for Jackett to favour his vice-captain, whose career spans more than 400 games,
The Keepmoat Stadium outcome was a 2-1 Pompey victory, representing a second-straight League One victory.
And Jackett admitted it was close which of the full-back challengers received the nod.
He said: ‘I wanted to get as much experience at the back as we could, clean sheets if possible, and we feel Lee brings a lot of that.
‘It’s unlucky for Brandon, he hasn’t done a lot wrong, but in terms of Lee and his personality and experience, that was my selection on Saturday.
‘He had one good run down the wing, that’s quite a feature of his play and we want to encourage that.
‘It didn’t happen that much on Saturday, whether that’s because it was his first game back or the fact they had most of the possession and he had to do a defensive job, I’m not sure.
‘But I am pleased to say it worked and it’s good to have him back. I do think we have two good left-backs in Lee and Brandon.
‘I felt it was needed, certainly in a back four that has leaked some goals and not produced enough clean sheets.
‘Brandon has done well, he is a good player and a good left-back, it was a difficult decision to choose between the pair on Saturday.
‘Lee just got the nod on experience and has brought quite a lot to us.
'It was quite a close call – I am happy with both of them.’
Haunstrup was utilised in the centre of defence at Oxford United in the Leasing.com Trophy on Tuesday night.
With Brown not involved, that allowed Joe Hancott to line up at left-back in the 2-2 Kassam Stadium draw.
The outing represented a 48th Pompey appearance for Waterlooville's Haunstrup.
And Jackett has sympathy for the 22-year-old’s current predicament.
He added: ‘Brandon wants to play full seasons because that’s what he’s been missing, but he has to keep working away and be ready when his chance comes.
‘He is disappointed, but took it professionally. He is disappointed, though.’