Schafer took over last September and, after guiding the Indomitable Lions to this year's African Nations Cup, must now plan a way to beat his own country in Group E.
"Germany is the strongest team in our group, so it's good we have a German trainer," Eto'o told BBC Sport Online.
"Schafer will help us master the skills we need to face the Germans.
"Our performance at the World Cup will depend on him."
Eto'o also believes the team can re-enact the magic of the 1990 side which reached the quarter-finals in Italy.
"We've had the same squad since 1998, so that's a plus," he said.
"But we have to realise that for every tournament it means starting from zero, from afresh.
"Theoretically, we're in an easy group but the proof lies in our playing."