Maatsen has remained with Chelsea for the first half of the campaign after he enjoyed a successful loan spell with Burnley last season.
The Dutchman made 39 Championship appearances for the Clarets, contributing four goals and six assists to help Vincent Kompany's side win promotion to the Premier League.
In contrast to last season's loan spell, Maatsen has found regular game time hard to come by under Chelsea boss Mauricio Pochettino.
Maatsen, who has a contract until June 2025, has played just under 200 minutes of Premier League football this term, while he has been handed just two starting opportunities in the top flight.
Having struggled to establish himself in the Chelsea side, Maatsen has previously opened the door to a potential departure if he is unable to secure regular minutes at Stamford Bridge.
The uncertainty surrounding the player's future has led to links with the reigning European champions Manchester City.
Burnley are also believed to be interested in bringing Maatsen back to Turf Moor despite reports in the summer suggesting that he had turned down the chance to return to the club.
According to Dutch outlet Voetbal International, Dortmund have become the latest side to enter the race to secure the full-back's signature.
The report claims that the Bundesliga club have already opened discussions with Chelsea about a possible January deal.
While Dortmund are believed to be in talks with the Premier League club, it is currently unclear whether they want to recruit Maatsen on loan or on a permanent basis.
The German side are looking to bring in reinforcements after experiencing a difficult first half of the season,
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