"Attack wins you games, defence wins you titles."
You couldn't have put it more aptly than Sir Alex Ferguson. Sure, you don't win games if you don't score. But you don't lose them either if you don't concede. And the latter always has a more positive impact on the players' psyche going into a long season.
So who all contribute when it comes to defence? Well, everyone on the field! In an age where forwards actually form the first line of defence, the entire playing XI is responsible for stopping the opposition from getting on the scoresheet.
That being said, defenders play a crucial role but when even the back line is taken to the cleaners, the man between the posts has to stand all.
Indeed, we see goalkeepers come up with some fantastic outings to win games on their own for their side. The heroics of the likes of David de Gea, Manuel Neuer, and Jan Oblak is well documented.
However, what about the men sitting on the sidelines waiting for their chance to take the field? What about the second-choice keepers who, despite getting scanty playing time, are expected to deliver a good outing whenever called for?
We look at five such goalkeepers who in spite of being second in the pecking order have delivered time and again when their team has needed them to.
#5 Sergio Romero - Manchester United
The Argentina No. 1 was roped in by the Red Devils on a free transfer at the beginning of the 2015-16 season. This was the same summer when the famous fax machine saga of David de Gea would play out.
While Romero did start the first few games of the season for Manchester United, who were then under Louis van Gaal's tutelage, De Gea's failed transfer episode meant that the former Sampdoria shot-stopper would be moved to the bench. It has been that way since then.
Romero has featured in two UEFA Champions League games for the Old Trafford outfit but it is really the cup ties where he has thrived this year. The Argentine has kept a clean sheet in all the four FA Cup games he has played for United.
Romero also kept a couple of clean sheets in the Carabao Cup and conceded only twice. Unfortunately, though, those two goals came against Bristol City on a fateful night at Ashton Gate.
While Romero may lack discipline at times, his short-range shot-stopping ability is one of the best in the world.
#4 Jasper Cillessen - Barcelona
Netherlands No. 1 Jasper Cillessen's most remembered World Cup moment, unfortunately, involved him giving way for Tim Krul for the penalty shootout against Costa Rica in the quarterfinals of the 2014 World Cup.
At the club level though, Cillessen has done much good for the sides he has represented. The Dutch shot-stopper, who currently plays as second-choice to Barcelona's German shot-stopper Marc-Andre ter Stegen joined the Blaugrana from Ajax in the summer of 2016.
Limited mainly to the Copa del Rey, Cillessen has kept six clean sheets from the eight games he has played so far. Having conceded only two goals in over 720 minutes of game time in the competition, the former Ajax man has been one of the core reasons behind Barcelona's rather easy road to the final of Spain's premier cup competition.
Cillessen is an able stopper of both long and short range shots, all thanks to his incredibly quick reflexes. He even chipped in with a clean sheet in the UCL when he shut out Sporting CP in the group stage of the competition.
#3 Wojciech Szczesny - Juventus
Wojciech Szczesny played two seasons for AS Roma on loan from Arsenal since 2015 before being signed on a permanent transfer by Juventus once the loan deal with the Romans expired in the summer of 2017.
At 27 years of age, Szczesny plays as the perfect back-up for the ageing veteran Gianluigi Buffon and is also touted to replace him once the Italian hangs up his boots.
The Polish shot-stopper has been almost impermeable between the sticks keeping a total of 13 clean sheets from the 17 games played across all competitions. Szczesny has conceded only six goals in over 1500 minutes of footballing action.
While he may not be a good anticipator of crosses, Szczesny's close-range abilities more than make up for this shortcoming of his. Having a distribution accuracy of 82 percent for the season, the former Arsenal man is one of the best passers of the ball.
#2 Nick Pope - Burnley
When veteran keeper Tom Heaton suffered a shoulder injury in September of last year, second-choice option Nick Pope was called to the fore for a Burnley side who rely more on their defence than offence to accumulate points in the Premier League.
The 25-year-old has been nothing short of a phenomenon this season, having kept a total of 10 clean sheets in the Premiership for the Clarets which is a joint fifth-best in the league. He has also made a total of 89 saves which is the joint sixth-best in the EPL.
Having little experience of playing in the top flight before this year, Pope has certainly taken the Premier League by storm and has held his own against some of the best players in the world, thanks to his incredible shot-stopping capabilities. He has averaged over three saves per game.
Pope has been immensely crucial to Burnley's good run in the EPL this year. Such has been the meteoric rise of the English goalkeeper that he is now in contention for the England squad that will travel to Russia despite many big names such as Jack Butland, Jordan Pickford, and Joe Hart all vying for a spot.
#1 Sven Ulreich - Bayern Munich
Early on in the season, Sven Ulreich would have been nowhere near this list. The German shot-stopper was so prone to mistakes that he cost Bayern several points in the Bundesliga.
His most notable mishap came against Wolfsburg in September last year when he fumbled a Maximilian Arnold free-kick into the back of the net. The shot was right at Ulreich and should have been a normal catch. Even in Bayern Munich's thrashing in Paris, Ulreich should have arguably saved two goals out of the three scored.
However, Ulreich has now gotten past his early season blues and now leads the Bundesliga with 10 clean sheets. Replacing a heavyweight in Manuel Neuer is never easy but the former Stuttgart man has been up to the task.
Ulreich's biggest skill is his reflexes, with him having already made some brilliant saves for Bayern Munich during this season. He is a great penalty saver as well, having kept out three of the four penalties conceded by the Bavarians in the Bundesliga so far. Like Szczesny, Ulreich is also a good distributor of the ball with an accuracy of 76 percent in the German top flight.