Porto goalkeeper Iker Casillas was left frustrated by a number of refereeing decisions in the aftermath of his side's 2-0 defeat to Liverpool in their Champions League quarter-final first leg clash.
The 37-year-old, who continues to perform well at the highest level after 20 years at the top of the game, highlighted a poor challenge from Reds forward Mohamed Salah, who was perhaps lucky not to be shown a red card after a dangerous stamp on Porto's Danilo Pereira.
He also shared on his official Twitter account an image of full-back Trent Alexander-Arnold handling the ball in Liverpool's box, though again the home side went unpunished despite the presence of VAR.
Soy 100 por 100 optimista!! Teniendo en cuenta los resultados de octavos de @ChampionsLeague no podemos pensar que la eliminatoria está perdida. Falta el juego en Dragao y vamos a luchar por pasar a las semifinales. Gracias a todos los portistas por el apoyo en Liverpool!! pic.twitter.com/3w1xst6ULP— Iker Casillas (@IkerCasillas) April 9, 2019
The decisions indirectly cost Porto, as they suffered a 2-0 defeat after early goals from Naby Keita and Roberto Firmino. The talk after the game was about the decisions, though, with the Portuguese side, and Casillas, clearly aggrieved.
Alexander-Arnold's potential handball was the first incident under the microscope, with Liverpool escaping punishment despite the use of VAR, in stark contrast to Tottenham's Danny Rose who was penalised for handball against Manchester City in the night's other quarter-final tie.
Furthermore, Salah's reckless challenge on Pereira was also overlooked despite the Egyptian clearly making studs-up contact above his opponent's ankle.
Following significant calls on social media for Salah to have seen red, former Premier League referee Mark Clattenburg spoke to the Daily Mail about the decision, saying: "The Liverpool forward comes over the top of the ball and clearly plants his studs onto the shin of his opponent.
"UEFA guidelines on this type of challenge are clear – anything with studs above the ankle is a red card.
"The VAR should have sent the referee to the review area, where I am sure he would have decided that Salah should be sent off."
Despite Salah's poor challenge, the Liverpool forward will be eligible to play against Porto in the next leg of the UCL quarter-finals on Wednesday 17 April.