The long-term injury to Gerard Pique has left Barcelona's squad short in defence. With Samuel Umtiti still not fully recovered from a knee problem, Clement Lenglet and Ronald Araujo are now the only fit centre-backs in the squad.
Araujo has only just returned from an injury -- he was an unused substitute at the weekend -- so Ronald Koeman has been forced to use B team defender Oscar Mingueza in the last four games.
Mingueza has done well and has made Barça re-consider whether they need to sign hin January. They're limited financially with what they can do and won't even have a new president until Jan. 24
The club's main target is Manchester City's Eric Garcia, but difficulties in agreeing a deal with the English club for the defender, who's out of contract next summer, are hampering a potential deal.
That's where the name Antonio Rudiger comes back into play, according to the network ESPN.
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The Chelsea and Germany centre-back was put forward as an alternative to Eric Garcia in the summer but Barça decided to stick with what they had.
Rudiger now offers the option of a defender who can come in and perform immediately in both the league and the Champions League.
He is out of favour at Stamford Bridge, where he's made just four appearances under Frank Lampart. With his contract up in 2022, he would be available for cheap in January, or maybe even on a loan until the end of the season.