Mauricio Pochettino could be set to lose Ian Maatsen from his squad (Picture: Getty)

Borussia Dortmund are reportedly ‘confident’ of signing Chelsea star Ian Maatsen in the January transfer window, either permanently or on loan.

The 21-year-old came close to leaving Chelsea in the summer but rejected a £31.5m move to Burnley on transfer deadline day.

Maatsen has since struggled to secure a regular spot in Mauricio Pochettino’s XI, normally featuring off the bench in the Premier League so far this season.

Dortmund have already expressed an interest in signing Maatsen in the upcoming window and are in negotiations with Chelsea.

The German side are optimistic the deal will get done although it is not currently decided if Maatsen will head to Dortmund on a loan deal or in a permanent move, according to The Telegraph.

It is thought that Chelsea wish to sell Maatsen but Dortmund would prefer to initially take him on loan, although an agreement of some kind is expected.

Maatsen is believed to be open to joining Dortmund, who currently sit fifth in the Bundesliga, 15 points behind leaders Bayer Leverkusen.

Ian Maatsen is believed to be open to joining Borussia Dortmund (Picture: Getty)

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Speaking earlier this month, Pochettino admitted that Maatsen had struggled to progress after impressing during Chelsea’s pre-season campaign in the summer.

‘Young players sometimes they can impress you in pre-season but you need to give them time after to relax. Sometimes they struggle,’ Pochettino said.

‘He’s in our squad and a great kid. He’s got great quality and can play in different positions but it’s about giving him time. he came from Burnley last season in the Championship. To perform at Chelsea, with all respect, is not the same and the competition is different.’

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The player is believed to be open to the move.