The international minnows face the world and European champions on Tuesday and their coach says they will have to produce an incredible performance to get a result
Valdes' team sit 46th in the Fifa world rankings, and are not expected to take anything from the friendly fixture on Tuesday, but Vicente Del Bosque's decision to rest key players could work in Panama's favour.
"The best thing to take on Spain would be to allow us to play with 22 players inside of 11," Valdes joked to Marca.
"Against Spain it is absurd to think of it as just another day and just another team.
"You can't approach them head on. Everything we try to do in games will have to be doubled. Twice the attention, the concentration, the effort, helping each other out and so on."
Chelsea star Juan Mata, who has been recalled to the Roja squad as a result of Del Bosque's rotation, had only positive things to say about the opposition coach - who used to play for his boyhood club.
"Dely Valdes played for Real Oviedo," he explained.
"I have seen the goals he scored in their Tartiere stadium. He is the image of football in this country and I am sure his team will play with the same footballing spirit he had."