Jude Bellingham's father reportedly attempted to confront the manager of his other son, Jobe's, team after the teenager was hauled off at half time during Borussia Dortmund's chaotic Bundesliga opener.
The 19-year-old midfielder, who joined Dortmund this summer in a £32million move from Sunderland, started Saturday's clash away at St Pauli but was withdrawn at the interval by Kovac after an ineffective first half.
According to Sky Sports Germany, Jobe's parents – Mark and Denise – were left unimpressed by the decision and waited in the tunnel after the 3-3 draw, where Mark, who also acts as his son's advisor, held an emotional discussion with Dortmund sporting director Sebastian Kehl.