El Submarino Amarillo only returned to the Spanish top tier this season but have made an excellent start to the campaign, with their Argentine centre-half having been a key performer.
The 23-year-old has played every minute of his side’s 16 league games, helping them to secure 28 points, which leaves them fifth in La Liga.
His excellent displays have alerted much attention, with City, Chelsea and Barca thought to be at the very front of the queue for his signature.
Both of the English sides are believed to be looking at adding to their defensive options next month, with their respective managers keen to strengthen to push for the Premier League title.
Jose Mourinho is known to be in the market for a new enforcer, with the future of David Luiz far from clear, while Manuel Pellegrini is looking at bolstering his options after Vincent Kompany’s injury woes unearthed a slight lack of depth in the position earlier this season.
However, the duo could be set for disappointment with Barca particularly interested in the South American – who is seen as a potential replacement for Carles Puyol.