Koscielny, who has been out with an Achilles problem, has not featured for the north London club since he played the full 90 minutes of the 2-0 defeat by Chelsea at the start of October.
The French defender joined the rest of Arsene Wenger’s side as they were put through their paces at the Gunners’ London Colney training base ahead of their group-stage clash at Emirates Stadium.
Arsenal need only a point to reach the last 16 for the 15th consecutive season as they face a Borussia Dortmund side who booked their place with victory on matchday four.
The teams are in the same Champions League section for the third time in four seasons. Dortmund were 2-0 winners in Germany on matchday one, Ciro Immobile and Pierre-Emerick Aubameyang scoring either side of half-time.
Here are some of the best pictures from Tuesday’s training session at London Colney.
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