Chelsea are determined to hold on to Andreas Christensen and will reject any approach in January, despite the 22-year-old's lack of first team opportunities under Maurizio Sarri.
It has been a frustrating season for Christensen, whose only Premier League appearance came in the 2-1 defeat at Wolves earlier this month.
He has started all of Chelsea's matches in the EFL Cup and Europa League, including their win over Bournemouth on Wednesday, so Sarri clearly views him as an important squad player who will be needed as the fixtures come thick and fast in the New Year.
For this reason, the Daily Mail reports that Chelsea are prepared to take a hard line stance on Christensen and will tell Barcelona that he is not for sale if they make good on rumours of a bid for the Danish centre back.
Ernesto Valverde has been seeking defensive cover for the injured pair of Samuel Umtiti and Thomas Vermaelen, and Barcelona's interest in Christensen dates back to 2015, before Chelsea loaned him out to Borussia Monchengladbach.
However, Barcelona have agreed a deal to sign Valencia defender Jeison Murillo on loan until the end of the season, which should ease their defensive concerns and possibly end their interest in Christensen.
Christensen, who has been on the books at Stamford Bridge since the age of 16, made his first team breakthrough last season as he played 40 times for Chelsea in all competitions.
Sarri has chosen Antonio Rudiger and David Luiz as his centre back pairing this season, leaving Christensen third in the pecking order, ahead of Gary Cahill.