The Toon face two crucial games in three days this week, with a trip to take on Metalist Kharkiv swiftly followed by a crunch Premier League clash with Southampton.
Pardew believes that striking the right balance between league and cup will be vital to ensure that his side do not become embroiled in a relegation battle.
He told The Sun: "We have to sit down and make sure we get team selection right.
"Southampton is a huge game and so is the second leg of this tie. We know there's a tail-off of energy from Thursday to Sunday."
The Magpies need a positive result against Kharkiv in the second leg of their last-32 tie following a frustrating 0-0 draw at St James' Park last week.