Pierre-Emerick Aubameyang has cast doubt on his Borussia Dortmund future after saying he did not understand why his club had suspended him for turning up late for training. Dortmund dropped their star striker from the squad for Friday's Bundesliga match against Stuttgart. Last year, the club suspended Aubameyang for a Uefa Champions League match against Sporting Lisbon after he flew to a party in Milan without permission. <strong>_____________________________</strong> <strong>Read more:</strong> <strong>_____________________________</strong> "I could understand why I was suspended for Milan because I did not respect the rules, but this time I am truly baffled. I did not want to arrive late," he told German newspaper <em>Bild</em> in an interview published on Friday. <em>Bild </em>said the player was suspended because he was 20 minutes late for training. German media have also speculated that he was suspended for again leaving Germany for a night out, this time in Barcelona. "For disciplinary reasons Aubameyang will not feature in the team for tomorrow's game," Dortmund said Thursday on the club's Twitter account. The club made no mention of the nature of Aubameyang's misdemeanour. The Gabonese forward is the club's top marksman with 10 Bundesliga goals so far, but he has failed to score in three league games and two Champions League matches, a barren spell that has coincided with a slump by the club. After three defeats and a draw in the Bundesliga, Dortmund have seen their five-point lead atop the Bundesliga turn into a six-point deficit to bitter rivals Bayern Munich. Borussia are also heading for elimination in the Champions League.