The reigning champion endured a miserable World Cup in Russia, crashing out at the group stage with two defeats from three games, FourFourTwo magazine reported.
Low called up three new faces in Thilo Kehrer, Kai Havertz and Nico Schulz for their first UEFA Nations League match against France on Thursday, although the majority of the squad comprises his usual favorites.
And former captain Matthaus said the coach must be prepared to drop any player who does not perform against Les Bleus or in the friendly with Peru in Sinsheim.
"I expect some clear messages from Jogi Low in the future," he wrote in his Sky column. "These can and will be unpleasant truths for some players.
"But just as Niko Kovac moderates things at Bayern Munich, so must Jogi Low. No rewards for past achievements. Stop the unquestioning loyalty."
Matthaus has questioned the decision to include Julian Draxler in the latest squad, with the Paris Saint-Germain midfielder struggling for game time and having failed to make an impact at the World Cup.
"Julian Draxler would certainly have earned a break. At PSG, he plays no supporting role at all," Matthaus said.