And the one-time Fratton Park manager knows his side will need to be at their best defensively if they are to get the better of their in-form visitors.
The Blues are in rampant form at present and travel to the Imps in the hope of extending their seven-match winning run in all competitions.
Thirteen goals have been scored in that period as Kenny Jackett’s side maintain their pursuit of honours on three fronts.
And six of which have arrived via set-prices, providing Pompey with a serious threat from both corner-kicks and free-kicks around the opposition penalty area.
Birmingham loanee Steve Seddon has been credited as the catalyst in this form of attack, with the left-back’s deliveries key to that recent success rate.
However, Appleton believes central defensive duo Christian Burgess and Sean Raggett are just as important as he prepares his side for what the Blues will throw at them at Sincil Bank.
The Imps boss said: ‘It (set-pieces) is one part of what they are good at.
‘We have to be resolute in those situations, you have to defend them well but first and foremost you have to not give silly free-kicks away.
‘Burgess is obviously very strong in the air and everyone knows Raggett here so we know that it is a big part of their armoury and it is something Kenny has been very good at as a coach down the years.’
Defender Burgess has scored two of those set-piece goals - against Bolton and Barnsley respectively - and has been credited with assists in two of John Marquis’ efforts.
The former Doncaster Rovers and Milwall striker is currently on his best run of form in a Blues shirt following five goals in his past six outings.
And with Kenny Jackett also able to call on the likes of Ellis Harrison, Ronan Curtis, Andy Cannon, Marcus Harness, Ryan Williams, Gareth Evans and Brett Pitman to vary his attacking options, Appleton knows it’s another aspect of Pompey’s game he has to be wary of.
Admiring what his opposite number has at his disposal at Fratton Park, Appleton added: ‘They have got some good players as well, in those forward areas, players that most managers would be happy to take if given the opportunity.
‘Them still being in the FA Cup and the Leasing.com Trophy just goes to show the strength in depth they have got in the squad and the size of the club.
‘At the start of the season when we went down there they were having a bit of an indifferent
‘Since then they have been climbing up the table and probably now are where they think they should be, around the play off places.’
‘I think now they have got more confidence and they will come here expecting to win the game.
‘It is going to be a difficult game.’