There is a reason why Iker Casillas is nicknamed 'San Iker' - which translated from Spanish means 'Saint Iker'.
He is a goalkeeper that has been known to perform miracles during his extraordinary 20-year career and for him to be between the sticks for Porto's Champions League quarter-final against Liverpool is another divine achievement.
At 37 years young, Casillas boasts a list of honours that most players can only dream of - including three Champions League trophies and five La Liga titles with previous club Real Madrid, plus a World Cup and two European Championships for Spain.
While critics may argue that fellow modern greats such as Gianluigi Buffon, Manuel Neuer and Edwin van der Sar were better goalkeepers, the trio put together have won the same amount of Champions Leagues as Casillas.
He made his first-team debut at Real Madrid as an 18-year-old in 1999 and he had only just turned 19 when he kept a clean sheet in the Champions League final victory over Valencia.
That signalled the birth of a Champions League beast, who has now played the most matches in the competition (175) and has the joint-highest amount of wins (101) alongside Cristiano Ronaldo.
Casillas' 57 clean sheets in 175 Champions League matches eclipses Buffon and Van der Sar (both 51) and he is the only player to have reached the knockout stages on 19 occasions.
There is no doubt he is the greatest goalkeeper in the competition's history and his performances in helping lead Porto to the last eight have been instrumental.
While the end of his illustrious playing days are in sight, Casillas recently signed a one-year extension with an option for another at Porto - a deal that could see him in goal for the club at the age of 40, when he plans to hang up the gloves.
And now he will be on Europe's biggest stage once again against Liverpool in a tournament that only he has played in for 20 straight seasons.
It wasn't that long ago that it appeared his time at the top of the game was coming to an end as his Real Madrid departure was followed by a period out of the Porto starting XI last season.
Having spent his entire career at the Bernabeu, the shot-stopper was forced to leave the club in 2015 for Portugal after his form waned and tensions grew, with first Diego Lopez and then Keylor Navas winning the battle to be the club's No.1.
Many thought Casillas' golden days were over and despite joining a team that had won 27 Primeira Liga titles, Benfica clinched the league in his first two campaigns at the club.
The situation continued to deteriorate last season when an angry Casillas was frozen out of the first team after coach Sergio Conceicao criticised his performances in training.
"I can’t close my eyes on two weeks of training that did not reach my expectations and Iker cannot understand this," Conceicao told the media.
"He didn’t train with the energy that I demand."
Casillas was sat on the substitutes' bench for Porto's next 20 matches in all competitions and it appeared that at the age of 36, his career and time in Portugal was winding to a close.
But 'San Iker' wasn't done just yet as he forced his way back into the No.1 role and won his first Primeira Liga title with the club.
Now he faces one of his biggest challenges against Liverpool's deadly front three of Mohamed Salah, Sadio Mane and Roberto Firmino.
Casillas played against the Reds on four occasions while at Real Madrid, most recently in 2014 when he kept two clean sheets as the Spanish giants won 1-0 at home and 4-0 at Anfield.
However, it's not all been fond memories for the shot-stopper as Liverpool crushed his Madrid team twice in the 2008-09 round-of-16 stage, with Casillas conceding five goals without reply - including four at Anfield.
This current Liverpool team are capable of similar performances, having scored 89 goals in their 43 matches across all competitions, and it's likely to require a stunning effort between the sticks to keep them out.
Porto have a rich Champions League history themselves, winning two titles - including the 2003-04 edition under Jose Mourinho.
And with Real Madrid, PSG and Bayern Munich already eliminated this time around, the Portuguese giants will believe they can go deep into the competition and cause a few surprises.
Thus, the stage is set for the ageless Casillas to once again show us why he is called ‘San Iker’.