The Blues boss has discussed his options as he aims to fill the void created by Thompson's return to Millwall.
Dion Donohue, Gareth Evans, Andy Cannon and Adam May are the players vying for a starting role in the middle of the park against Blackpool.
Filling Thompson's boots after Millwall recalled him from his loan is a big ask for whoever is given the nod at Fratton Park.
But Jackett is confident he has players to step in alongside Tom Naylor and make their mark.
He said: '˜The options are Haunstrup in and Donohue into midfield, Cannon straight in, May straight in and Evans dropping back.
'˜With Ben going they are the options I have for this weekend.
'˜You do impact the team if you do that (move too many players around).
'˜It's clear, consistent selection and clear, consistent formation. The fewer changes the better.
'˜When you feel you have to change, whether through poor form or assessing someone in the week, injuries or suspensions, you do.
'˜But not changing it too much is the ideal.
'˜It took Ben a couple of weeks to get match fit and he was leggy in one or two of the early games.
'˜Then he grew in confidence and with his fitness came a rhythm.
'˜We've got other strengths, though, and as a club you can't get fixated on one player.
'˜It moves on and you have to adapt and be good enough to do it.
'˜I do think we have the players to do it.'
Cannon will be hoping to make his Pompey bow against Blackpool after spending his first week training with his new club following his arrival from Rochdale.
The 22-year-old has stated he sees himself as an attacking midfielder, but Jackett believes he could be used in any of the central roles in his side's 4-2-3-1 formation.
Jackett said: '˜He's an out-and-out midfield player with a bit of everything.
'˜But I do see him as a central midfield player.
'˜The manager does well at Rochdale. He does change tactics and formation so the players have to be adaptable.
'˜So for Andy, although he's predominantly a midfield player, he's played lots of roles.
'˜I see him as an out-and-out midfield player whether he's competing for two places or three.
'˜We've mainly played 4-2-3-1, that's the preferred formation, and, for him, he can come into any of the three midfield positions that are available.'