Pompey boss Kenny Jackett is wrestling with a left-back conundrum ahead of the trip to Oxford United.
With Tareiq Holmes-Dennis expected to miss three to four months through injury, the Blues are on the hunt for a replacement.
In the meantime, Jackett is weighing up an alternative from within his current playing squad.
Drew Talbot switched from right-back to stand in for Holmes-Dennis during the remaining 51 minutes of the opening-day victory over Rochdale.
At Cardiff in the Carabao Cup on Tuesday night, promising left-back Brandon Haunstrup was handed the seventh outing of his Pompey career.
Both come into the equation for tomorrow’s visit to the Kassam Stadium.
When you put a right-footer over to the left it works for maybe one, two or three games, but over a period of time you need a natural left footKenny Jackett
However, Jackett has ruled out Kal Naismith filling in as he prefers the left-footer in an attacking role.
He said: ‘We’ll see if Drew plays there, he certainly won’t let you down if he did.
‘I would prefer a natural left-back and a natural left-footer, but if I need to play Drew there then he really won’t let me down.
‘When you put a right-footer over to the left it works for maybe one, two or three games, but over a period of time you need a natural left foot.
‘So while I am happy that Drew will always give you 100 per cent and do well, a specialist in that position would be my preference.
‘Particularly as almost all of the contenders for the wide-left positions are right-footed as well.
‘Kyle Bennett has generally played wide left which he considers his best position, while we also have Milan Lalkovic and Jamal Lowe.
‘Perhaps Naismith is an option there, but for me I think he is better in the goal-scoring positions.
‘Brandon is a left-footed left-back and did okay against Cardiff. I was disappointed he came off with cramp, but that’s the way it is and I understand that. It’s something a young player, physically, has to come through.
‘He needs to get battle-hardened and that is part of the reason why I do feel we need some back-up and some competition for him.
‘Brandon must now get mentally and physically battle-hardened so he can play for three hours, if needed.’
Naismith has experience of operating at left-back for Accrington before his 2015 move to the south coast.
He also featured three times there for Pompey last season – but Jackett has other plans for the Scot.
He added: ‘Kal at left-back is something people have mentioned.
‘But I see him as an attacking player and think he can score goals.
‘I would rather keep him focused at the front part of the pitch because goals are so hard to come by.’