The home side are fighting for their Bundesliga status, winning just one of their last 10 matches and lying two points shy of safety.
A 2-0 midweek defeat to fellow-strugglers Nurnberg was particularly painful for Stuttgart, and Klopp knows they will scrap hard on Saturday for the points they so badly need.
"Stuttgart are in a real relegation battle and that's why it's going to be an intense game," he told Dortmund's official website.
"Apart from one place (top spot), all others are still up for grabs.
"We have to be prepared that it's not going to be a friendly."
Dortmund were also in action in midweek, drawing 1-1 with Schalke - a result which ensured Klopp's men stay a point and a place above their local rivals in the battle to finish second behind champions Bayern Munich.
And the Dortmund coach reported no injuries following that match, saying: "Physically my team looked extremely fresh and lively. That is valuable information, knowing all my players are in top shape."
Stuttgart coach Huub Stevens saw Mohammed Abdellaoue return to training this week and the forward will undergo a late fitness test on his hamstring ahead of the match.
Despite his side's worrying predicament, Stevens remains upbeat and has every faith they can still escape the bottom three.
"We talked about the way we lost against Nurnberg and the job now is to learn from our mistakes," he told Stuttgart's official website.
"The good thing about playing in midweek is that straight away you have the chance to put things right.
"I continue to have confidence in the team. It's obvious there is some uncertainty among the players but we can dispel that if we remain together.
"I hope the players show ambition against Dortmund and play to the level they have in them."