When Simon Mignolet arrived on Wearside he was a little known, Belgian under 21 international, signed from the relative obscurity of a Belgian side called Sint-Truiden. If or rather when as seems to be the case, his transfer to Liverpool is completed, he will leave as an established Premier League player and a full international.
Replacing a player of his quality will not be easy but Sunderland have a habit of finding good goalkeepers. In fact, one potential successor to the number 1 spot could already be found within the squad in the shape of Keiren Westwood.
Westwood has not been given many opportunities to shine on Wearside, finding his route to the starting XI blocked by the incredible form of Mignolet. When he has played, results have been mixed. His shot stopping is unquestionably of a high standard but some of his decision making can be on the erratic side.
A prime example of this was in Martin O'Neill's first game in charge, which resulted in a win for the Black Cats over Blackburn Rovers. While losing 1-0, Westwood made a hapless attempt to claim a long punt up field and while there was nothing wrong with the goal that resulted from the incident, it was mercifully ruled out by the officials. This is not an isolated incident as far as Westwood is concerned either, though it is the one that springs to mind most readily.
In fairness to Westwood, the man he's looking to replace has dropped the odd clanger himself. Even in the midst of a wonderful run of form, Mignolet blundered against West Brom in remarkable fashion, handing the Baggies a head start on their way to a 4-2 victory at the Stadium of Light. He continued to play and bounce back. It is much harder for a goalkeeper to come in and play a handful of games as the Irishman has had to, so it would be unfair to judge him too harshly on incidents like the one above.
If given the chance to take the number 1 spot, Westwood must show that with a consistent run in the side, mistakes are the exception rather than the rule. At the age of 28 it is make or break time for him at the club and for his stalling international career.
It's quite possible he has done enough in training to show Di Canio that he is a readymade replacement for Mignolet and that the money received for the Belgian can be invested in the other areas of the paper thin squad. Whether Di Canio has been sufficiently impressed by Westwood remains to be seen, but even if he does decide that the Irishman is capable of becoming first choice, it's likely that another goalkeeper will be sought out to compete for the number 1 shirt while also providing much needed back up.
Currently on the books Sunderland have the recently signed Polish prospect Maksymilian Stryjek, as well as young Englishman Jordan Pickford, both of whom are highly rated. However, if Westwood were to pick up an injury it would be a huge risk to throw either of the two teenagers into Premier League action with so little experience under their belts.
Three names who have been recently named in relation to Sunderland in recent weeks exemplify the different types of option open to the hierarchy in their pursuit of another goalkeeper.
The first option would be to sign someone older - a veteran even - such as Morgan De Sanctis. The Italian is 36 years old and with that age comes a wealth of experience. He may only offer a couple of seasons, but that might be all that is needed before Pickford or Stryjek are ready to step up and become genuine competition for the first XI.
De Sanctis is a full Italian international and was part of the squad that went to the Euros in Poland and Ukraine last year. Though he only possesses a handful of caps, it is less of an indication of his ability and more to do with the fact one of the all-time greats Gigi Buffon occupies the number 1 shirt. Like many other excellent goalkeepers over the years, De Sanctis has been robbed of more caps by the talent ahead of him.
Aside from international recognition, De Sanctis has played at the top level in Italy for the majority of his career - with a short sojourn to Sevilla that saw him loaned to Galatasaray - and has resulted in him playing Champions League football as recently as two seasons ago for Napoli.
At his age, were De Sanctis or another veteran of his ilk to be signed, they would probably want a decent share of first team football with the clock ticking on their career. As a short term solution, it's certainly not a bad one as it would cost the club little or nothing in terms of a transfer fee. Given the amount of football a veteran would want to play, it could cause unrest if Westwood is retained but only as second choice.
Alternatively, Sunderland could reinvest most, if not all of the money in an established goalkeeper who is making a name for himself at present. This type of player is typified by Fraser Forster, who like De Sanctis has big game experience in the Champions League, while his recent call up to the England squad means his price tag would certainly be at a premium rather than a bargain.
With the squad seemingly so weak in other areas and money needing to spent to add quality and numbers in almost every position, spending big on someone like Forster would probably necessitate further sales to generate revenue to fund other signings.
If Forster was signed, it would not be the first time the club have invested big money in a goalkeeper from north of the border; Craig Gordon arrived from Hearts for a significant sum of money and with a glowing reputation. A large transfer fee - rightly or wrongly - equated to unrealistic expectation amongst supporters. While Forster has looked the part in the Champions League, he would have to establish himself on a weekly basis in a stronger league to meet the kind of expectations his fee would generate. The risks are obvious.
Another linked to the club this summer is a lesser known stopper by the name of Grzegorz Sandomierski. He would likely come cheaper than Forster and at two years younger than the 25 year old Englishman, would also represent an investment with potential sell on value should he prove himself.
He spent last season on loan at Blackburn Rovers from parent club Genk and has previously attracted interest from the likes of Swansea City. Sandomierski would much more likely be signed as a backup to Westwood, offering competition for places, hoping to shine when afforded the opportunity and establish himself in the way Mignolet did after Craig Gordon suffered several injuries. Whether he would be capable of making that step up is difficult to predict.
Breaking it down in this way is to perhaps oversimplifying matters but they seem to be the obvious routes down which the club can go. Each has their own merits and risks and there is of course the possibility that like Mignolet, Westwood could be sold too, which might necessitate two goalkeepers arriving. Even in that instance, spending big seems the least likely option. Finding the right bargain, young or old, will not be easy but there is every reason to be confident that the club will get it right.