Despite persistent claims that the centre-back is on the verge of extending his contract past 2022, the Denmark international now has less than seven months remaining on his contract.
Head coach Thomas Tuchel has acknowledged his frustration with the situation, and that has seemingly led to the 25-year-old spending time out of the team in recent weeks.
Commenting on Twitter, Italian journalist Fabrizio Romano claims that Barcelona and Milan are ready to take advantage if fresh terms have not been finalised by the end of the year.
While Barcelona cannot afford to sign Christensen in January, they are keen on a free transfer and would jump at the chance to hold discussions over a pre-contract agreement.
Meanwhile, Romano says that Milan may be tempted into an approach as they look to find a replacement for long-term injury absentee Simon Kjaer. body check tags ::