The defender, currently at the Copa America with Argentina, has been linked with a move to Manchester United.
“Valencia know very well what I want,” he told ESPN. “From there, every word my agent says is obviously with my authorisation.
“(My agent) fully has my authorisation to speak with whoever he needs to.
“I’ve had a talk with the president and my agent, and he knows very well what my wish is, but for now I’ve told my agent that my head is here and I’m leaving it in his hands, to do what he needs to do.”
Centre-back Otamendi enjoyed another superb season at Valencia, playing 38 times and scoring six goals as they finished fourth in La Liga.
He started this week as Argentina beat Uruguay 1-0 in their second group game at the Copa America, following a 2-2 draw with Paraguay in their opener.
Otamendi began his career in his home country with Velez Sarsfield, and moved to Porto in 2010 before switching to Valencia in 2014.