The 27 year old plays for Fiorentina and made just 11 Serie A starts last season.
The defender began his career with Boca Juniors before moving to Fiorentina in 2012 on a free transfer. Although he is a centre back he can also play in the right back position.
James Tomkins is currently sidelined with a hamstring injury but is hoped to be fit by Saturday while James Collins is suspended due to his red card against Spurs last weekend.
Winston Reid has yet to commit his future to West Ham by signing a new five year contract on improved terms.