UEFA have said they will "enter discussions with FIFA and IFAB" over a possible change to the rule which saw Julián Álvarez's penalty disallowed in Atlético Madrid's Champions League last defeat to Real Madrid on Wednesday.

Real Madrid progressed to the quarterfinals -- where they'll face Arsenal -- thanks to a 4-2 penalty shootout win following extra time at the Metropolitano, after the tie had finished all square at 2-2 on aggregate.

A key moment in the shootout saw Álvarez's spot kick ruled out after VAR determined that the Atlético forward had kicked the ball twice -- once with each foot -- as he slipped before scoring past goalkeeper Thibaut Courtois.

That led to protests from Atlético, with coach Diego Simeone insisting that "the ball doesn't move" and challenging journalists over the decision in his post-match news conference, and Courtois hitting back, accusing Atlético of "crying."

"Atlético de Madrid enquired with UEFA over the incident, which led to the disallowance of the kick from the penalty mark taken by Julián Alvarez at the end of yesterday's UEFA Champions League match against Real Madrid," UEFA said in a statement.

"Although minimal, the player made contact with the ball using his standing foot before kicking it, as shown in the attached video clip. Under the current rule (Laws of the Game, Law 14.1), the VAR had to call the referee signalling that the goal should be disallowed.

"UEFA will enter discussions with FIFA and IFAB to determine whether the rule should be reviewed in cases where a double touch is clearly unintentional."

IFAB is the International Football Association Board, a body which is responsible for the laws of the game and any proposed changes.

The Álvarez incident led to confusion inside the stadium on Wednesday, with many present initially unaware that the spot kick had been disallowed, and then post-match protests by Atlético, led by Simeone.

Atlético had dominated Wednesday's encounter for long spells, having won 1-0 on the night thanks to Conor Gallagher's goal after just 27 seconds.

The club have never come out on top against local rivals Real in the Champions League, losing the 2014 and 2016 finals, and being eliminated in the 2017 semifinals.