The Video Assistant Referee [VAR] was once again in the firing line after another controversial night in the Champions League.
UEFA brought forward the use of the technology for the last-16 stage of this season's competition , and the controversial system has caused more consternation.
In the first round of fixtures, Ajax were furious after their opening goal against Real Madrid were ruled out for a controversial offside call .
But on Wednesday two sides were a victim of the technology.
Leading via Sergio Aguero's goal, the hosts had the chance to draw level when Nicolas Otamendi handled Daniel Caligiuri's goal-bound shot.
A corner had seemingly been awarded but VAR intervened to give a penalty, delaying the game being restarted by nearly three minutes before Nabil Bentaleb was permitted to step up to make it 1-1.
"The spontaneity of football is in danger of being lost here. We want quicker decisions, please."
And he was not the only one to be confused by the time taken to make the call:
VAR needs speeding up. Wait far too long for this VAR decision. No communication of process on big screens until final verdict. Boos all round at delay until cheers from Schalke fans when VAR signals handball and penalty. Bentaleb pen 1-1 #SchalkeCity
— Henry Winter (@henrywinter) February 20, 2019
Definitely think the Man City-Schalke ref is taking all this time doing VAR reviews and admonishing players just so his haircut can get plenty of air time. Betting Bentaleb hits up the ref for his barber's number at halftime. He should.
— Ives Galarcep (@SoccerByIves) February 20, 2019
Not a lot of point having VAR if refs need to take 3 mins to know if its a handball or not! Incompetency of the highest order 🙄
— Matt Le Tissier (@mattletiss7) February 20, 2019
Three minutes to get a VAR decision wrong. Good this innit?
— Jonathan Smith (@jonnysmiffy) February 20, 2019
VAR making a decision in the Schalke v City match. pic.twitter.com/F2tj8xsY0N
— Paddy Power (@paddypower) February 20, 2019
When you slow it down everything becomes a penalty/shifty/ evil looking. If you slowed down man landing on the moon VAR would overrule it and book Armstrong
— Barney Ronay (@barneyronay) February 20, 2019
I don’t like VAR because I think there needs to be a world where Diego Costa gets away with villainy.
— Musa Okwonga (@Okwonga) February 20, 2019
VAR is the worst thing to happen to elite football since Roman Abramovich
— elliot ross (@FutbolsaCountry) February 20, 2019
Central to the delay was a problem with the pitch-side screens which officials can refer to help make decisions.
Those monitors were out of action which prevented Cerro Grande from giving an immediate decision, forcing the significant delay in Gelsenkirchen.
The referee couldn’t check the pitchside screen regarding the Otamendi handball because it was faulty. He relied purely on the word of the VAR, which probably isn’t ideal for such a borderline decision
— James Robson (@jamesrobsonES) February 20, 2019
By the end of a remarkable opening 45 minutes, Schalke had turned the game around when Bentaleb struck home a second penalty after Fernandinho was adjudged to have tripped Salif Sane - this time given without the assistance of VAR.
Though City were aggrieved and later lost Otamendi to a red card in the second half, they turned the game around late on via a stunning free-kick from Leroy Sane and a smash-and-grab winner from Raheem Sterling in the 90th minute to win 3-2.
In Spain, there was further indecision as VAR got involved again.
Felipe Luis crossed from the left and the on-loan Chelsea forward rose above Giorgio Chiellini to thump into the top corner.
But after the celebrations had concluded, official Felix Zwayer was urged to consult one of the pitch-side screens - in full working order in the Spanish capital - before resuming play.
Morata appeared to put two hands on Chiellini as he headed home, leading to the Italian throwing himself to the floor.
And German ref Zwayer was swayed by the centre-back's reaction and awarded Juve a free-kick.
Naturally, the incident did not escape the watchful gaze of many on Twitter.
Fair to say VAR decisions not going Atletico's way recently - after Madrid got benefit of any doubts going in the recent derbi... especially Morata goal / penalty call in that game.
— Dermot Corrigan (@dermotmcorrigan) February 20, 2019
Another huge VAR moment. The most ambiguous of the game, for me. Great header by Morata, too. But if nothing else, the ref was quick with his decision - as he has been with all of them.
— Paolo Bandini (@Paolo_Bandini) February 20, 2019
— shawarmapapi (@moaizmq) February 20, 2019
VAR had already come to Juve's aid when Mattia de Sciglio's foul on Diego Costa in the first half was adjudged not to have taken place inside the penalty area, after Zwayer had given a spot-kick to the home side.
Much like City, Atletico emerged from the ashes of the VAR mess to prevail to make themselves favourites to progress to the quarter-finals.
After Jose Gimenez had given Diego Simeone's side the lead, centre-back partner Diego Godin doubled the lead via a deflection off Cristiano Ronaldo, to give the La Liga side daylight ahead of the second leg.