Bayern Munich were on the receiving end of a withering attack from Marco Reus after the Borussia Monchengladbach winger snubbed them in favour of a move to rivals Borussia Dortmund in the summer.
The Germany international was on the brink of signing for Bayern in a £14m deal before the move fell through at the last minute alerting champions Dortmund who swooped for the highly rated player.
Reus has been credited with being the driving force behind Gladbach's remarkable resurgence in recent years as they have changed from relegation favourites to genuine title contenders in just 12 months.
Bayern insist talks broke down due to his unacceptable demands during negotiations such as a guaranteed start in every game.
But Reus has hit back at their claims over the failed switch and warned the famous old club he will let his football do the talking when his current club face them on 20th January.
"I will see them for battle on the pitch," he told the Bild newspaper. "I know what the truth is and that is all that matters.
"If they want to think that, then let them think it - it does not bother me. In my eyes, Dortmund are the better club.
"I decided this way because I feel there is more potential (in Dortmund) for playing in Europe and measuring myself against the best."