Borussia Dortmund have signed defender Ian Maatsen on loan from Chelsea until the end of the season, the Bundesliga club announced on Friday.
The Netherlands youth international made his Premier League debut last August and has made 12 appearances in the league this season.
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"Because of our current squad situation we decided to act on the left-back position this winter," Dortmund sports director Sebastian Kehl said in a statement. "Ian fits our profile with his strengths."
"He has a lot of pace, a strong left foot and can play various positions."
Maatsen, 21, is Dortmund's second signing of the January transfer window, following Jadon Sancho's return to the club on loan from Manchester United on Thursday.
Dortmund head coach Edin Terzić told reporters on Friday that he is not ruling out the possibility of Sancho making his second debut for the club in their match against Darmstadt on Saturday.
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"We are happy that Jadon is finally with us. He had a lot of fun on the training pitch. He is healthy, he has trained a lot in the last few weeks. We will use the session again today and see how far he is," Terzić said.
Last season's Bundesliga runners-up, Dortmund have struggled in the league and sit in fifth place, 15 points behind leaders Bayer Leverkusen and six behind fourth-placed RB Leipzig, who occupy the last Champions League spot.
They have, however, advanced to the Champions League knockout stage where they face PSV Eindhoven -- one of Maatsen's youth clubs -- in the round of 16 next month.
The Bundesliga resumes on Friday after a three-week winter break.