The Colombia international only recently made the move to Napoli, but the Lisbon giants are considering luring him to Portugal this summer
The Portuguese giants are looking to sign a new left-back this summer and have previously been linked with Real Madrid's Fabio Coentrao, who is believed to be looking for a route out of the Santiago Bernabeu.
However, they are also keeping tabs on Armero and might see the Colombia international as a cheaper alternative.
"Benfica have not directly contacted us, but they have done so via an intermediary," Ramalho told A Bola.
"I have informed Pablo about it and he reacted with excitement. Benfica are a top club.
"Everything's possible in football, but Napoli have only recently purchased him. We will have to wait and see if Benfica's interest is concrete."
The defender, 26, joined Napoli from Benfica in the January transfer window and has a contract with the Partenopei until June 2016.