Medina, 21, could arrive for a fee in the region of €5m with talks reportedly at an advanced stage.
The Argentina under-23 international is a versatile defender capable of playing at centre-back or left-back.
He has played 18 times this season for Talleres and perfectly matches the profile sought by Lens coach Franck Haise.
Haise intends to use a 3-5-2 system next season and believes Medina will fit in perfectly as the left-sided centre-back.
He is the third Talleres player who could be heading to Europe this summer.
And star striker Nahuel Bustos is on the radar of Roma, Sevilla, Valencia, Real Sociedad and Bordeaux.