With the German league title race set to go to the wire, Bayern Munich's Mario Gomez has stirred things up by sending a former team-mate a video message after scoring against rivals Dortmund.
Bundesliga leaders Dortmund drew 4-4 at home with VfB Stuttgart last Friday with the equaliser coming from Stuttgart's Christian Genter in the 92nd minute.
Ex-Stuttgart striker Gomez sent his former team-mate a specially recorded message of thanks on Bayern's behalf for beating the league leaders at home.
After Bayern's 1-0 win at Nuremberg on Saturday, Dortmund's lead at the top of the table has been cut to three points with six games left and the two teams are set to clash at Borussia's Signal Iduna Park stadium on April 11.
"Mario congratulated me straight after the game," Gentner told German daily Bild.
"But it wasn't just by SMS. With a couple of Bayern players, he had filmed a whole video message."
Genter refused to reveal the nature of the message. "I'm not saying what it contained, but I liked it," he told the Stuttgart Zeitung.
Gomez watched the Dortmund-Stuttgart game in the Bayern team hotel with his Munich colleagues and was quick to praise Gentner, with whom he played through the Stuttgart junior ranks up until the Bundesliga squad.
Meanwhile, Dortmund defender Mats Hummels has said he is amused by the attention coming from Munich.
"Honestly, I have to say I am amused by the banter from Bayern," the centre-back told Bild after Bayern president Uli Hoeness said the game in Dortmund will be the 'moment of truth'.
"The war-of-words is at a similar level to the battle for the title. Nothing has happened yet which is below the belt. It shows we have gained respect and how we are perceived by Bayern.
"We are still ahead and we will have a highly-explosive end to the season, which is the best the fans could hope for", added Hummels.