The 2014 World Cup winner warned Julian Nagelsmann’s side risk early knockout elimination unless defensive issues are fixed and key players rediscover form.
Germany topped Group E after a 7-1 win over Curacao and a 2-1 victory against Ivory Coast.
They also lost 2-1 to Ecuador in their final group match despite an early goal from Leroy Sane. drawing heavy pundit criticism.
"It has to be nasty to play against us, meaning we need to be capable of defending well and being gritty. We aren't doing that yet. And we need Musiala and Wirtz in top form - which we don't have right now,” Kroos said on TikTok Live show .
"If both of these things don't change, we won't last much longer. We used to have matches where we played poorly too - like against Algeria. But we were still able to win those bad games. I don't think this current team has that in them.
"This is a group that gives everything. However, I don't agree with the coach saying that (complacency) had absolutely nothing to do with it. You always have that in the back of your mind when you've already qualified. You can't just block it out; it's completely human. We are simply not a physical team."