Loew said on Wednesday he had failed in his attempts to contact the Arsenal midfielder and that he had been notified of Ozil's international retirement by the player's advisor.
Germany have failed to qualify from the group stages at a FIFA World Cup finals for the first time since 1938.
Of the problems Loew has to fix, Neuer is not one and he had little to do in the second half as Germany pushed for an equaliser that never came.
Germany start their campaign against Mexico in Moscow having won just one of their six friendlies since qualifying for Russia 2018
Turkish President picture puts Mesut Ozil under pressure for Germany's FIFA World Cup opener against Mexico
Ozil and Manchester City's Ilkay Gundogan were whistled by German fans in pre-World Cup friendlies after posing for a photo alongside President Recep Tayyip Erdogan last month.
The two players of Turkish descent have been dealing with a barrage of criticism in Germany after they were pictured with Erdogan.
The public backlash over players mixing sport and politics ensured the Germany squad left for its World Cup defense under a cloud of its own making.
The Germans took off from Frankfurt in pouring rain hoping captain Manuel Neuer will stay fit after eight months on the sidelines with a foot fracture.
Gundogan caused a political storm last month, by meeting Turkey president Recep Tayyip Erdogan and handing over a Manchester City shirt signed to "my president".
Ozil will sit out the friendly against Saudi Arabia in Leverkusen with light bruising to his left knee, but was able to run in training on Thursday.
Germany now suffered back-to-back defeats after also sliding to a 1-0 loss to Brazil in Berlin in March.
Ozil was the target of a Twitter jibe from the city's police constabulary when Stoke beat Arsenal 1-0 earlier this season.
Arsenal edged past Newcastle 1-0 to end a three-game winless run in the Premier League after a fine strike by Mesut Ozil from the edge of the penalty area.
The 29-year-old is out of contract at the Emirates Stadium at the end of the season.
Mesut Ozil has defended himself against criticism of his attitude and says his nonchalant body language can be misleading.