The Blues are heavy favourites to defeat their non-league opponents, sitting 57 places higher in the football pyramid.
Pompey are fourth in League One while the the Linnets are 13th in the National League standings.
But Kenny Jackett will treat his side's opponents with as much respect as any other team they’d face.
The Pompey boss has admitted he’ll be fielding a strong side in a bid to reach the third round for a third successive season.
However, he did admit he could give some players who he feels need a breather a rest ahead of a long trip to Blackpool on Tuesday.
We’ve predicted the Blues’ starting line-up and bench to face King’s Lynn...
1. Goalkeeper - Craig MacGillivray
Had another fine evening on his 101st appearance against Oxford. MacGillivray played in the first-round tie against Ipswich and there seems little reason why things will change on Saturday. Will be desperate for a clean sheet after his past two goals conceded have been penalties. Photo: PinPeP
2. Right-back - Callum Johnson
It wouldn't be a big shock to see Haji Mnoga start but Kenny Jackett won't want to make too many changes to his back four. Johnson's crossing ability could prove key against a Lynn side who will look to counter. Photo: Joe Pepler
3. Centre-back - Sean Raggett
Been ever-present in the league this season and scored the winner against Ipswich. Comes up against his old housemate from his Lincoln days, Adam Marriott. Photo: Daniel Chesterton
4. Centre-back - Rasmus Nicolaisen
Jack Whatmough's not long back from a hamstring injury, which came after playing a lot of games. King's Lynn play with two strikers up front, which would be an ideal challenge for Nicolaisen as it's an area of his game he needs to develop. Photo: Graham Hunt