Borussia Dortmund chief executive Hans-Joachim Watzke has highlighted Mats Hummels' honesty in making public his desire to join Bayern Munich, stating the defender has "behaved impeccably".

Hummels came through the ranks at Bayern before joining Dortmund in 2008, initially on loan, and has gone on to make close to 300 appearances in all competitions, winning two Bundesliga titles and one DFB-Pokal in the process.

The Germany international, whose contract expires at the end of next season, is now hoping to secure a return to the Allianz Arena in a move that has angered the Dortmund faithful.

Watzke, however, was keen to indicate Hummels had followed the right process in admitting his wish to leave and urged the Dortmund fans not to target the 27-year-old in Saturday's home game with Wolfsburg.

He told the club's official website: "I understand many fans are disappointed. Nevertheless it is important for me to make clear that Mats has behaved impeccably.

"He has been open and honest with us at all times."

Dortmund go into Saturday's game with Wolfsburg seven points behind Bayern and needing a win to stand any realistic chance of catching Pep Guardiola's men in the title race.

Watzke would rather the fans' focus was on cheering their side to victory rather than directing their ire at captain Hummels.

"I would be very happy if the disappointment of the BVB fans would not be used towards hostility against Mats," he added. 

"He would not deserve it after being in the middle of a great story for eight and a half years. 

"Also, we are currently at a key stage of the season with good prospects. We can reach the highest points ever achieved and bring home the DFB-Pokal crown when we face Bayern in the final on May 21."

Watzke reiterated that despite Hummels' wish to go, the player would be going nowhere until a satisfactory offer was received from Bayern.

"There is no update. An absolute pre-requisite for this transfer to happen this summer is that Bayern match our demands. I have not seen that yet," he said.