Negredo is set to be cashed in by Sevilla this summer.
"It is my obligation to look at the market," Gil Marin told ABC.
"Falcao leaving the club is an important possibility, therefore I have to advise and ask to speak with different people.
"We will talk about it at the end of the season. There is enough time to assess what is suitable for all parties. Up front Negredo is one of the options presented to us by the market. We all know what level he is at."