A win for the home team at the Mercedes-Benz Arena on Sunday would reduce that gap to two points and Voller fully expects Stuttgart to make inroads sooner or later to challenge his side for a place in Europe next season.
"Stuttgart will rise again," he said. "To be realistic, Bayern Munich and Borussia Dortmund will decide the title between them and we want to be one of the five or six teams who challenge for a place in Europe.
"Schalke, Hamburg, Bremen, Wolfsburg and currently Frankfurt are there, and I also reckon with Stuttgart."
Stuttgart have made a habit of starting the season slowly only to end it on a high, which is why Voller is not so surprised that his side's hosts are inside the bottom three.
However, he also knows that does not reflect the true potential within their fellow Europa League participants' side.
"They have had a difficult schedule," he added on the Stuttgart website. "The pressure soon grows.
"This is not the true face of Stuttgart what we are seeing now and we know that, which is why it will be a tough game.
"I just hope that Stuttgart get out of this rut after tomorrow [Sunday]."
Stuttgart boss Bruno Labbadia hopes it happens sooner than that after being let down by his side again on Thursday.
A 2-0 defeat in Molde means the Swabians are not only struggling in the Bundesliga, but also in the Europa League.
"I am terribly disappointed," said Labbadia. "You can see that the players are pulling themselves down."