The newly promoted side remain unbeaten after eight games and climbed to second place in the table following their 3-1 win over Werder Bremen at the weekend, two points behind leaders Bayern.
And Hummels has urged the German champions not to underestimate the threat from the club bankrolled by Red Bull if they are to defend their title this season.
“RB Leipzig have a squad that could cause us trouble,” Hummels was quoted as saying by Sport Bild.
“I definitely expect Leipzig to make the top six at the end of the season.”
Thomas Muller, meanwhile, agrees that Ralph Hasenhuttl’s men should not be taken lightly, but feels Borussia Dortmund remain Bayern’s main rivals for the title.
“Of course, RB Leipzig should be taken seriously,” Muller added. “The quality and depth of teams is decisive and Leipzig are looking good in this area.
“But I continue to see Dortmund as our biggest rival. They will be challenging us again toward the end of the season.”