Brewster, the Golden Boot victor at the Under-17 World Cup in October, was incensed after being targeted by a Spartak defender during Liverpool's 2-0 win and had to be dragged away by team-mates and staff on the final whistle.
The striker then spoke to referee Mohammed Al-Hakim regarding alleged racist abuse from a Spartak defender in the closing stages of the clash.
UEFA found Spartak guilty and punished the club with a partial stadium closure for their next UEFA Youth League fixture.
After the final whistle, the youngster had to be restrained by teammates of members of Liverpool's staff as he tried to confront the player.
Steve Clifford out indefinitely with health issues, Stephen Silas to take over
Silas, who served as a scout and an assistant for Charlotte from 1999-2002, re-joined the franchise in 2010. The team did not specify the issue Clifford is dealing with and said there is no timetable for his return.
Liverpool won the contest, played at Tranmere's Prenton Park ground, by a 2-0 score-line, thanks to goals from Curtis Jones and George Johnston.
Anfield officials will now make an official complaint to Uefa.
Steven Gerrard, the former Liverpool midfielder who now coaches the club's youth team, said: "It's hard for me to comment on it right now. It's something that the club will look into and deal with", the Reds idol said to reporters. I don't want to take any gloss off that because he was superb.
In September, Liverpool's Nigeria-born attacker Bobby Adekanye was subjected to racist chants and gestures from Spartak supporters in Moscow.
The Russian side travel to Anfield needing a win in order to make it through to the last-16 stage of the competition, now sitting third in Group E ahead of the final matchday.