That means Louis Thompson and Ryan Tunnicliffe look likely to start at New Meadow.
But circumstances dictate former triallist Mingi could find himself thrust into unexpected first-team action – not long after appearing set to complete his maiden Fratton Park season on loan at National League Maidenhead.
The 21-year-old made nine appearances for the Magpies over the first half of the campaign.
He impressed under the tutelage of Alan Devonshire – prompting interest from Wrexham – until a hamstring cut short his stay at York Road.
Pompey have now taken the decision to retain his services as they try to cope with their midfield problems.
And with Mingi having less than five months to earn a new Blues deal, Cowley has challenged the youngster – and others in a similar boat – to make any decision on his future an easy one for him.
He said: ‘Jay is a young player, he's had a successful loan spell with Maidenhead in the National League.
‘Our plan was for him to go out and continue to play because it’s what he needs in his personal development, but the opportunity has arisen now with the squad size the way it is so we will keep him with us.
‘I’ve seen many times in my career, injury crisis creates an opportunity for a young player and a lot of player’s careers have started off the back of difficult moments with either squad sizes or injuries.
‘There’s a real opportunity for Jay and I look forward to him grabbing the opportunity with both hands.
‘For all of our players that are out of contract, there is motivation for them to earn another contract because this is a great football club and a brilliant place to play football and many people would love to play at Portsmouth.
‘It’s up to the young players and the other players that are out of contract to go and grab that opportunity.
‘The decisions are made by the players, not by us, but by the players, by the way they train and the way they play.
‘For me they always control their future's in terms of their performances.’