Chelsea on alert as Borussia Dortmund consider putting Pierre-Emerick Aubameyang up for sale

Borussia Dortmund are considering putting Pierre-Emerick Aubameyang up for sale in the January transfer window after growing fed up of his disciplinary issues, according to reports.

The Daily Mirror says Chelsea are among a number of clubs who have been sounded out by Dortmund about the Gabon striker's potential sale in January.

The Bundesliga giants are reported to be unhappy with Aubameyang's poor timekeeping, with the 28-year-old alleged to have arrived 20 minutes late for final preparations before a game against Stuttgart earlier this month.

Dortmund dropped the striker for the trip to Stuttgart, citing "disciplinary reasons".

Aubameyang was also suspended by the club for a Champions League game against Sporting Lisbon in November last year after he took a trip to Milan without the club's permission.

Reports say the 28-year-old striker took a similar trip to Barcelona earlier this year with the club's permission, but he returned late.

After the suspension against Stuttgart, German newspaper Westdeutsche Allgemeine Zeitung cited a source inside the Dortmund dressing room as saying that Aubameyang "allowed himself numerous lapses of discipline, arrives late for training constantly and considers himself untouchable".

The Gabon striker said earlier this month he could not understand why he was suspended for the Stuttgart match.

"After Milan, I could understand the suspension and fine because I broke a club rule. But I don't understand it this time – I didn't want to turn up late," Aubameyang was quoted as saying by ESPN.

Aubameyang has netted 11 goals in 12 Bundesliga appearances for Dortmund this season. He became only the second African player to the win the Bundesliga Golden Boot last season after finishing with 31 goals.

The Gabon striker tried to force through a move away from Dortmund during the summer and publicly invited Real Madrid and AC Milan to make bids for him.

However, no transfer materialised and the 28-year-old reaffirmed his commitment to Dortmund.