In late November 2013, Guardiola was angered to see his tactical plan the Bundesliga match at Borussia Dortmund -- a crucial fixture in the title race at the time -- were made public by German tabloid Bild.

The Spanish coach reportedly warned his players that he would trace the mole, saying that "heads will roll" once the perpetrator has been found, while Bayern CEO Karl-Heinz Rummenigge indicated that the club might sell the "mole" if they were found.

According to Sport Bild, Guardiola admonished Kroos and striker Mandzukic -- who reportedly denied Guardiola a handshake -- in the dressing room and hinted they may lose their respective places in the team by saying: "I was brought here to make decisions. You are entitled to be annoyed -- but not in public for everyone to see.