Diego Simeone taunted fans of Real Sociedad before his Atletico Madrid side were knocked out of the Copa del Rey.
The Spanish champions travelled to the Anoeta for the last 16 tie.
But their team bus was attacked as they headed towards the stadium, with Simeone leading the response.
The Argentine, who is not shy of confrontation, took to the front of the vehicle and gestured to the opposition supporters.
The bus continued to edge forward despite being pelted with various objects.
Simeone was later asked about the incident and said: "You all saw what happened outside. We were en route, alongside the Real Sociedad fans. I imagine they're always in that position. Suddenly the [police] protection wasn't there. You saw that.
"It didn't affect the game at all. When the game started I said to [Real Sociedad coach Imanol Alguacil] that it had absolutely nothing to do with him.
"But he should send my regards to whoever had to prepare, and didn't prepare, whatever that was."
Real Sociedad ran out 2-0 winners thanks to goals from Alexander Sorloth and former Manchester United man Adnan Januzaj.
Atletico are experiencing an indifferent campaign and look certain to relinquish their domestic crown.
Simeone's side sit fourth, level on points with Real Sociedad and last week lost in the Spanish Super Cup to Athletic Bilbao.
They have been drawn against Manchester United in the last 16 of the Champions League having edged out Porto and AC Milan in the group stages.
The 51-year-old renewed his contract last year, keeping him at the Wanda Metropolitano until 2024.
He's already been in charge at Atletico for over a decade but recently addressed the club's current state on social media as they deal with a challenging year.
He said: "Today we are going through a difficult time in terms of results and, from what I feel, I want to convey to you that being together, from fans, footballers, managers and coaching staff, we are going to continue fighting for our goals!!"
