Thursday's news that Gabon striker Pierre-Emerick Aubameyang had not made the trip to Berlin for the Bundesliga match against Hertha spread like wildfire through the usual social media outlets.

"Aubameyang is training in Dortmund," BVB sporting director Michael Zorc announced via the club's Twitter account before the team boarded the flight bound for the capital on Thursday evening.

"We have the impression that his mind is being occupied by other things and that he is therefore not completely focused.  This calls into question whether he could be of help to us in Berlin."

Zorc also conceded that the ongoing Aubameyang saga was a "difficult situation" for the club.

Just hours earlier, it seemed a good bet having missed Dortmund's scoreless draw at home to Wolfsburg last weekend, the 28-year-old attacker would be back in the squad.

"He wasn't an issue for us over the last few days," said head coach Peter Stöger who suspended Aubameyang for the Wolfsburg match after the striker had missed a team meeting. "We had a good, short talk on Monday. If nothing changes he's an option for tomorrow," Stöger concluded.

Transfer speculation heats up

It's not known what, if anything may have changed to affect Aubameyang's standing in the coach's eyes in the few hours that followed, but growing speculation about the goal scorer's possible imminent move to English Premier League club Arsenal couldn't have helped.

Earlier in the day, Zorc denied that BVB had been contacted by Arsenal over a possible transfer and expressed displeasure about comments made by the Gunners' manager, Arsene Wenger, who said that he believed the Gabon man would fit well into this squad.

Goal production difficult to replace

If Aubameyang does move before the end of the January transfer window, Dortmund, who are reportedly demanding €70 million ($85 million) for his services, will certainly miss his production up front. While he hasn't always been consistent, his 13 goals in 15 Bundesliga matches this season are second only to Bayern's Robert Lewandowski (15 in 17) and are more than double that of BVB's second-leading scorer, Maximilian Philipp (six in 11).

What Stöger and Zorc won't miss, is his at times undisciplined behavior off the pitch – Stöger, who took over from the sacked Peter Bosz just last month, was the third Dortmund coach after Bosz and Thomas Tuchel to find it necessary to suspend the Gabon striker in just over a year.