The Eintracht Frankfurt pair will be on a high after lifting the DFB Cup with the Eagles last month and ter Stegen has warned that they and El Tri must not be underestimated when the two nations meet in their opening World Cup fixture in Moscow on 17 June (kick-off 17:00CEST/11:00ET).
"Every one of us wants to win the World Cup and to do this, we want to get into the tournament with good feelings and with a good result against Mexico," said Barcelona's former Borussia Mönchengladbach custodian. "They are the strongest team in our group, together with us, and they've come a long way in recent years.
"We're going to prepare well in the coming week and we want to prove that we are the best team in the group."
Ter Stegen kept Germany's goal the last time the two nations met, at the Confederations Cup last year, and he conceded only one in a 4-1 victory for Joachim Löw's men. He will likely have only a watching brief this time around, though, with Bayern Munich's Manuel Neuer fit again and preparing to captain his country to glory in Russia.
"It's difficult for me, but I am giving all my support to the team so that we can win the World Cup, which is all that I want," added the 26-year-old, who will be ready as and when he is called upon over the coming month, to help Germany get their hands on the prize.
"It's not just about quality, but also fortune and your form on the day that matter," he continued. "There are many good nations, like Brazil and Spain, who are always up there, but we hope to start with a victory."
By beating Fabian and Salcedo, Germany's path to the knockout stage would be significantly simpler.