UEFA have ordered a partial closure of the Wanda Metropolitano to punish Atletico Madrid in their game against Manchester City.
The sanction comes after Uefa charged Atletico with “discriminatory behaviour” due to the behaviour of away fans at the Etihad last week.
Cameras caught supporters appearing to gesture Nazi salutes during City’s 1-0 win.
A group of around five men, dressed all in black and sat at the front of the second tier, were filmed repeatedly making the gestures.
And now Uefa have ordered the closure of a minimum 5,000 seats for the return leg which is set to take place on Wednesday.
The decision was made following an investigation by Uefa after it opened up disciplinary proceedings against Atletico.
Atletico were previously punished in a similar way after their fans unfurled a racist banner at the 2018 Europa League final.
A statement from Uefa read: “Atletico Madrid will inform, prior to the match, the sectors to be closed, which shall be at least 5000 seats.
“The club shall also display a banner with the wording ‘#NotoRacism’ with the Uefa logo on it.”
The ruling means only 63, 456 spectators will be allowed inside the stadium – but the allocation of the travelling City fans has not been affected.
It is a blow for Atletico who need all the support they can get to overturn a 1-0 aggregate deficit.
Kevin De Bruyne’s winner separated the two teams in the first leg but Pep Guardiola’s side dominated from start to finish with 15 shots and 71 per cent possession.
Atletico failed to produce a single shot in the match and defended resolutely until Phil Foden produced a moment of class to send De Bruyne through on goal.
But history is on the side of the Spanish champions who have never lost a Champions League tie after losing the first leg away from home by one goal.