Pierre-Emerick Aubameyang will not be able to play for Arsenal in the Europa League this season, much to the club's disappointment.
The Gunners had hoped their £56million January signing would be eligible to play for them in the competition, as he previously only featured in the Champions League with Dortmund.
Under normal circumstances he would be able to play in the competition, as he isn't cup-tied in the traditional sense, having not kicked a ball in the Europa League.
But because Dortmund dropped into the competition, after getting knocked out the Champions League group stages, Aubameyang is ineligible to play for Arsenal in case they come up against his former side.
The news is particularly frustrating for Arsenal for a number of reasons, not least because Alexandre Lacazette has been ruled out for six weeks with an injury.
The France international underwent knee surgery on Tuesday morning to solve what was an ongoing issue and even though the operation was described as a success it comes as a serious setback for the north London club.
The Europa League would have acted as the perfect stage for Lacazette to rebuild some of his shattered confidence, after losing his place in Arsenal's first team.
The Gunners also sold Olivier Giroud, Theo Walcott and Alexis Sanchez in January, meaning they are now left with few options in attack in Europe.
Not only this, but Sanchez, who left Arsenal for Manchester United last month, is eligible to play for the Red Devils, which will come as another kick in the teeth to the Emirates club.
The Chilean featured for the Gunners in the Europa League, and because there has been no cross over, will play in the Champions League with Manchester United.
Arsenal will line up against the Swedish outfit Ostersunds at Emirates Stadium. The Gunners are in round 32 of the Europa League and are seeking to win their first European trophy as well as qualifying for next season’s Uefa Champions League.