Police estimated that around 400 supporters flocked to Anfield Road in order to welcome both teams upon their arrival, despite being urged to stay away.
A bottle was reportedly thrown at the vehicle carrying Madrid players and staff, smashing a window in the process, as it drove towards the stadium on Wednesday evening. Only one pane of the double-glazed window was broken during the incident, meaning no one inside the bus was hurt.
After the 0-0 draw secured Real progress to the Champions League semis, Valverde declared: "It was nothing. I come from Peñarol, it's normal. It was nothing.
"It gave us extra motivation, and we thought 'Ok, now on the field we are going to go out to kill and to leave everything behind'."