Alex Bass has emerged as first-choice keeper since the turn of the year, a responsibility the 21-year-old has thrived in.
He has conceded two goals in six League One matches after being surprisingly recalled at Gillingham, including four consecutive clean sheets.
In contrast, MacGillivray has been employed solely in the Leasing.com Trophy, with the semi-final against Exeter taking place on February 18.
Pompey head to Coventry tomorrow night (7.45pm) for a crucial clash between promotion rivals.
And Jackett continues to oversee the intriguing battle between his keepers.
Pompey’s boss said: ‘I am pleased with both goalkeepers, their form this season has been good.
‘Alex has shown good improvement since I have been here, he has taken responsibility, kept his head down and worked very hard.
‘I don't think he has done anything wrong, similar to Craig, and we will see how this run goes, it's not something which is cast in stone.
‘Alex has a little bit of everything, he has a good maturity as well for someone who is 21, which is something that I do like.
‘Against Tranmere, he came out on one occasion and, whether the pitch caught him out, was caught in two minds.
‘I was pleased afterwards when the ball came into the box and he still stepped out and made a good punch away from oncoming attackers.
‘We also have Craig, that’s the thing, we’ll see where we are against Coventry, Shrewsbury or Exeter.
‘There are a lot of games coming up and, whoever I pick, I’m in a good position because both are good keepers.’
Bass now totals 14 appearances this season, registering six clean sheets in the process.
And with Scotland international MacGillivray challenging, Jackett believes it has created one of the strongest departments in his squad.
He added: ‘If you can get two players in every position then you’re in a good position as manager.
‘At the moment – and so far – it is quite a strong department. If we can get every department as strong as that that would be great.’