Have Celtic identified a Hart replacement in Vaessen?

According to Dutch media outlet Brabants Dagblad, the club have made an early move for the 28-year-old who is out of contract with relegation-threatened Waalwijk at the end of this season.

With current number one Joe Hart retiring this summer, reinforcements in the goalkeeping department will be high on the agenda for the Premiership Champions’ recruitment team now and in the coming weeks.

So, would Vaessen, who is also said to be attracting interest from Eredivisie rivals PSV Eindhoven, fit the bill as a potential Hart replacement? Here, using Wyscout data, we take a closer look at the Dutch keeper to find out more.  

Of course, it is worth noting that data never gives a full picture when analysing a player, even more so for goalkeepers who have much more limited data points compared to outfield players. Goalkeeper data is also more heavily influenced by team performance than any other position.   

There are still a few key metrics that can be used to evaluate goalkeeper performance and give an insight into their profiles.

Shot-stopping

Firstly, and arguably most importantly, is shot-stopping. Essentially, how well is a goalkeeper performing when it comes to their fundamental role, keeping the ball out of the net?

As can be seen in the above scatterplot, Vaessen is a standout in this season’s Eredivisie in his regard. He has, understandably given Waalwijk’s struggles this season, faced one of the highest volumes of xG against in the league (1.86 per 90). However, he has only conceded 1.52 goals per 90, giving him the highest prevented goals (0.33 per 90) of any goalkeeper in the Eredivisie. Prevented goals simply being the expected goals against minus conceded goals.

His overall prevented goals have been worth a 7.81 positive goal swing for his side. His ability to overperform versus the expected number of goals he ‘should’ have conceded has clearly been pivotal to Waalwijk’s efforts to remain in the Eredivisie this season.

From a shot-stopping perspective, this is by far Vaessen’s strongest season. Last season his prevented goals was 1, while in the 21/22 season, he was very slightly below what he would have been expected to save (-0.27).

Over his whole career, all of which he has spent with Waalwijk, Vaessen has a positive prevented goals total, conceding on average 1.51 goals per 90 from 1.56 expected conceded goals per 90.

For comparison, Hart has tended, generally, to concede around what he would have ‘expected’ to during his time with Celtic. Although this has been on the decline domestically and Europe has been a particular issue – Hart posted the lowest Shot Stopping percentage of any keeper in the competition this season, according to StatsBomb data.

Sweeper Actions

The next area where data can be used to provide further insight into Vaessen is sweeper actions. Here, the data shows Vaessen to be more of a sweeper-keeper. He has the third-highest exits per 90 (1.90) in the Eredivisie, almost twice as much as Hart has averaged this season (1.07 per 90). Some of this could well be accounted for by fewer attacks heading towards Hart’s goal than to Vaessen’s.

For aerial duels, Vaessen comes in around average for the volume he is involved in (0.38 per 90). However, as the below graphic shows, he does not rank too well against his positional peers for his win percentage (66.67 per cent).

At 6’2, Vaessen is not the biggest goalkeeper (Hart is 6’5) so dealing with crosses is perhaps not the strongest part of his game. It is worth bearing in mind here how small these volumes are, i.e. it would only take one or two successes, or failures, to swing these considerably.

Distribution

Not something Hart has been overly comfortable with during his time in Glasgow, Rodgers has, predictably, continued to use the goalkeeper in build-up phases during his second stint in the Celtic Park dugout. The following distribution scatterplot highlights some of Vaessen’s tendencies in this area.  

Heavily influenced by team style, Vaessen takes an even amount of short/medium and long passes, indicating Waalwijk vary their build-up play.

The above graphic from Wyscout sheds some more light, showing how successful Vaessen is in his passing from open play across various distances.

Here we can see he has only misplaced one of 139 passes at 0-20m in the last year. His overall Short pass accuracy of 97.77 per cent is average, to slightly above average, for a goalkeeper in the Eredivisie in the last 12 months.

The graphic also highlights that he isn’t quite as accurate over longer distances. This is usually the case for any player but his 59.5 per cent pass accuracy is below average for a keeper in the Dutch top-flight over the last year.

Given that Celtic don’t tend to go direct too often, Hart has only attempted an average of 3.24 long passes this season, this is potentially not a huge issue, should Vaessen make a move to Parkhead this summer.

Conclusion

Vaessen is an interesting link. His performances in this season’s Eredivisie, especially his shot-stopping, could be seen as something of a bit of an ‘overperformance’. Equally though, given his age, an argument could be made that this is down to him entering his peak years – late 20s to 30 is often considered peak for goalkeepers.

He potentially profiles as more of a sweeper-keeper, which would be advantageous given Celtic often holds a high line, domestically anyway. At 6’2, he perhaps doesn’t have the classic presence of a ‘big guy in goals’ so there may be some question marks over how he would potentially deal with the physical aspect of Scottish football though.

His distribution numbers seem steady enough. However, here it would remain to be seen how this scaled to a much more possession-dominant Celtic team compared to a side struggling in the Eredivisie that is averaging less of the ball than their opponents most weeks.

Going from facing an xG of almost two per game to around 0.67 (Celtic’s xG Against in the Scottish Premiership this season, Wyscout) would also be an adjustment for Vaessen. Out with European games, Celtic keepers may often only be required to make just one, maybe two, important saves a game.

This unique environment a Celtic goalkeeper finds themselves in, and some of the previously mentioned limitations of goalkeeper data, make coming to any definitive judgements here tricky.

However, what can be said is that Vaessen is a peak-age goalkeeper performing consistently well in a quality league. Off the back of his strongest shot-stopping season and showing signs of an ability to contribute effectively to the build-up and in sweeping, he would represent a promising candidate for next season’s Celtic number-one jersey.