The Whites, who are without a victory in nine games, sit 12th in the table, eight points off the top six.
Hernandez, speaking to the Yorkshire Post, said that the task faced by Paul Heckingbottom's side is a "simple" one.
"I think it is simple," the 32-year-old said. "We have in front of us 14 games.
"If you see the points [for the team finishing sixth] in the last few years, if we want to have a chance to finish in the playoff positions then we need to minimum win nine or 10 games. It is this simple."
Leeds are back in action on Wednesday evening with a trip to promotion-chasing Derby County.