The Citizens go into their final three games of the season with their destiny back in their own hands, and Demichelis claims that a win in the clash at Goodison Park will provide the whole club with a confidence boost.
"The most important thing is that it is up to us again," he told The Guardian. "Before we were wondering about others, now we can focus on ourselves.
"Everton is the key, it's a massive game and a difficult place to go. If we can win there it will give us a huge morale boost, and with Liverpool playing on Monday it could also have an impact on them."
Demichelis joined Manchester City last summer from Champions League finalists Atletico Madrid.