The German top-flight's biggest sides have struggled in European competition this term, with Bayern Munich, Borussia Dortmund and RB Leipzig combining to win just one of their six Champions League matches thus far.
Sammer, who left his job as Bayern sporting director in July 2016, has refused to put the Bundesliga's issues down to finances, pointing to the Europa League as an example.
"Our clubs lose against clubs with much less financial ressources in the Europa League," Sammer told Bild. "How would our international prestige be without Bayern and Dortmund?
"Unfortunately the Bundesliga lacks the highest level at the moment."
The financial issue was controversially raised by Bayern striker Robert Lewandowski after he criticised the German champions and their transfer policy last month.
The Polish striker told Spiegel: “Bayern has to come up with something new and be creative, if the club wants to keep luring world-class players to Munich.
"And if you want to keep up at the very highest level, you need these players’ quality.”
Bayern were subsequently thrashed 3-0 by big-spending Paris Saint-Germain in the Champions League – a loss that cost manager Carlo Ancelotti his job.
Sammer, though, thinks the league has bigger issues than a lack of spending.
"The Bundesliga has to take a look in the mirror," he said.
"German football should be more dealing with performances instead of hiding behind pretend discussions about money."
Domestically, Bayern are also off their usual best, having drawn two straight matches and sitting five points behind leaders Dortmund.