Every summer transfer window is seemingly a big one for Liverpool, but this one is perhaps their most important in recent memory.

In previous years the Reds have needed to address glaring issues and during Jürgen Klopp’s reign, the club have done just that.

The attack lacked pace, so Sadio Mané was brought in from Southampton. The attack then became too reliant on Mané for pace so Mohamed Salah was brought in from Roma.

In defence, a leader was required. Virgil van Dijk was identified and signed. Loris Karius and Simon Mignolet weren’t at the level required so Merseysiders went out and took Alisson from Roma.

This summer, however, is different. There are gaps in the squad, areas that definitely need improving, but there aren’t quick fixes as in previous years.

A reliable centre-back to partner van Dijk would top many lists given Joe Gomez, Dejan Lovren and Joël Matip have all struggled with injuries at various times throughout their Liverpool careers.

An understudy to Andrew Robertson is an important one for some people with it not being smart to have the Scotland captain playing every single match. Likewise with Trent Alexander-Arnold on the opposite flank.

Added depth would be nice but Liverpool have a squad capable of covering the full-backs with James Milner doing a job on the left and Gomez trusted on the right from time to time.

Midfield is pretty stocked with Jordan Henderson, Gini Wijnaldum, Alex Oxlade-Chamberlain, Naby Keïta, Fabinho and Milner all able to play a variety of roles in the middle third. Though another creator wouldn’t go amiss.

The one area of the team many would like to see improved is in attack. The front three of Roberto Firmino, Mané and Salah is one of the best in Europe, but beyond that the options are limited.

Xherdan Shaqiri’s blown hot and cold since his move last summer, though he is perhaps an ideal fifth choice attacker due to his flexibility and creativity. Daniel Sturridge, if reports are to believed, is leaving when his deal expires in the summer while Divock Origi is going to be rewarded for his performances this term with a new contract.

However, the Belgian has his limitations. The match winner against Barcelona, it’s hard to see him matching Salah, Mane or Firmino if he was to step in for an entire season.

Rhian Brewster is the wildcard and the club apparently have high hopes for him, but he’s untried and untested at first-team level. He should definitely be part of Klopp’s squad for the 2019/20 campaign but putting too much pressure on him can’t be a good thing.

What Liverpool need is a fourth attacker. A player not yet at superstar level but with the potential to be world class. Michael Edwards needs to unearth the next Salah and Mané. Someone whose game could improve under Klopp and in this team. But it isn't that easy.

With this in mind, we've pieced together a list of player who might be of interest to Liverpool. This wasn't simply a case of picking in-form players or star names. Instead, the Football Whispers lab was used to identify players over a two-season period who will tick the box.

Firstly, they had to be 24 or under. Those playing for rivals clubs were excluded and those with reported price tags above £80million were benched. From the list remaining a number of stats were analysed.

We're also looking for wide forwards meaning Timo Werner, despite being a perfect fit for this Liverpool team, has been left out.

Liverpool forwards need to be genuine goal threats, regardless of whether they're consistently prolific, as well as creators. So, the open play expected goal contribution (xGC) per 90 was a metric used to flag potential signings. This stat combines expected goals and expected assists.

Goals from inside the penalty area was also taken into account. If this percentage is high then it's more likely that their goals are repeatable and sustainable.

Touches in the opposition box was a key metric, too, with players needing to be able to be comfortable in these areas. It shows composure and it shows they're used to these situations easing the adjustment period.

As we're looking for the next Salah or Mané, their stats from the last two seasons with previous clubs were used as a base to go off. A select few of those can be seen in the graphics below. For added context, Salah's xGC prior to Liverpool was 0.68 and Mane's was 0.57.

For this list, we went with players with an xGC total of 0.43 and above, with a minimum of four touches in the box and a percentage of goals inside the area of 70 per cent or higher.

Top of the list is Federico Chiesa. Liverpool don't have the best track record when it comes to signing Italians but the club's last two from Serie A haven't turned out too badly in Salah and Alisson.

The Fiorentina man is 21 and has already been linked with a host of top European clubs due to his performances in the Italian top flight. As you can see from the graphic above, he isn't the most prolific, averaging just 0.21 goals per 90 over the past two seasons, and he's underperforming his xG90 total.

However, the fact he's getting into dangerous areas is positive. His finishing will improve with experience. He averages a high number of touches in the penalty area, the second highest of the players on this list, and his versatility is shown in his heat map.

His off the ball work may need to improve but that could be down to the fact Fiorentina like to play more of a counter-attacking style, so their aim is always to fully utilise Chiesa's pace and he isn't necessarily required to win the ball back in the final third.

His shot selection could definitely improve. He's averaging more shots per 90 than Mané does for Liverpool, but a number of his efforts are speculative.

This is apparent when you realise 77 per cent of his goals over the past two seasons have come from inside the penalty area.

It's way below Mané (100 per cent) and Salah (92 per cent) and could be an area improved upon.

Bailey was one of the most in-demand forwards last summer but his stock has dramatically fallen this year. Still only 21, there's a lot of potential to be crafted into an unstoppable wide attacker.

He's a long-term Liverpool transfer target, linked with the Reds while playing for Genk, so he's definitely going to be appearing on Edwards' list. The Bayer Leverkusen man, despite struggling this season, has still managed an average of 0.32 goals over a two year period. It's a fairly large sample size, too, having played in 4,140 minutes of Bundesliga action during that time.

He's outperforming his xG90 total due to the value he adds to his shots – it's something very few players his age are able to do. However, only 73 per cent of his 14 goals have come from inside the area. A large percentage have come outside the area.

More often than not, this is a bad thing but when you see he's only averaging 2.89 shots on a per 90-minute basis it's clear he's not wasting many shots and you can write off those that do miss the target because he adds unpredictability to the side.

Whereas Chiesa is more of a goal scorer, Bailey balances goals with chances created.

Another player linked with Liverpool in the past, Brandt is definitely more of a creator these days and is thriving as a No.8 for Peter Bosz new look Bayer Leverkusen side. In fact, on paper at least, he's ideal for Klopp's midfield.

But that doesn't mean he couldn't be just as effective in the forward line for the Reds.

His xG90 total of 0.22 isn't anything to write home about but the other stats show a few things. Firstly, he's outperforming his expected goals by 0.07 and 0.27 of his xGC comes from expected assists.

He's a creative force with an eye for a goal. Secondly, and perhaps even more importantly, he's only averaged 1.29 shots over the past two seasons. Liverpool's front three average a minimum of 2.5 meaning Brandt would have to increase that. His goal tally and expected numbers would rise off the back of this.

He turns 24 this month and while he'll never be a prolific scorer – though 93 per cent of his 16 goals have come from inside the area – he is the type of player who could finish the season with 20 goal involvements, and they're just as valuable.

Williams was tipped to be the next big thing in La Liga a few years back, and he was even on Liverpool's radar prior to them signing Mané if reports are to be believed.

There's an argument to suggest he's stagnated playing for Athletic Bilbao yet the numbers he's averaged over the two-year period are still impressive.

The 24-year-old isn't matching his xG90 average of 0.34 but he isn't that far behind it. He's averaged a goal every three and a bit games over close to 5,800 minutes in the Spanish top flight, showing he's consistent and reliable.

You also have to take into account the team he's playing for. They're mid-table. That isn't to say he couldn't overperform and catch the eye but for context, he's averaged the same amount of goals per 90 as Wilfried Zaha and Williams' xG90 is 0.10 better.

It's when you break down his shot map that the value of the Athletic Bilbao man really becomes apparent. He rarely wastes an opportunity by shooting from distance. A large number of shots are from good positions in the box, perhaps why 100 per cent of the 19 goals he's scored have come from inside the area, showing he's a danger.

This is an intelligent, versatile forward with pace to burn and he wouldn't break the bank. He ticks many of the boxes for a Liverpool attacker.

Bayern Munich reportedly dropped out of the race to sign the Lille man after he made it clear he wanted to move elsewhere. Liverpool are one of the clubs mentioned and though €80million has banded about, the Ligue 1 runners-up are likely to cash in for much less.

He's an intriguing player. The 23-year-old would improve the Liverpool squad, there's no doubt about that. But how would he impact the team?

The fact he's a penalty taker boosts his numbers. Not that it should be held against him, being calm from the spot is a good trait, but it's something to take into account when admiring his goal return. For context, eight of the 20 he's scored in Ligue 1 this season have been penalties.

However, he's still a threat. His open play xGC90 is 0.43. He's a goal threat and he can take penalties. What some might consider being a negative could be turned into a positive.

Another thing to take into account when considering Pépé is he plays the same position as Salah. He makes the same runs as Salah, angling himself between full-back and centre-back, and, like with all players, he likes to get the ball onto his favoured left foot.

Signing him could allow Salah to play as a centre forward again. Perhaps Pépé could even be deployed as the No.9. It's all theoretical for the time being and there's no guarantee he could function in the same team as the Liverpool No.11. He could well be too similar.

Having said that, however, the numbers still show him as a good fit, albeit not the best on the list.

This one is trickier to judge. All of the others have been in the same league for a minimum of two seasons so the sample size is fairer. Jota's only been in the Premier League for one season so he's being judged on that alone.

It's difficult not to be impressed by the Wolves man. Adept on both feet, he started the season slowly but has nine goals to his name this term for an average of 0.35 goals per 90.

He's slightly overperforming his xG90 but it shows his goal return is sustainable. All of his goals have come from within the penalty area and he's frugal with his shots, taking just ten from outside the box all season.

He plays as part of a two alongside Raul Jiménez but often drifts to the left flank, similar in many ways to Mané who starts left but likes to cut inside. Liverpool like to buy Premier League proven players and they realise it comes at a cost, but perhaps Jota is too rich even for them.

Wolves aren't going to want to cash in on one of their better players when they're trying to push for Europe and unlike other clubs, they're in no need to sell. If he was looking to move, he's the sort of player who would look right at home in this Liverpool side.

The 22-year-old has the perfect profile to be Liverpool's fourth attacker. He scores, he creates, he's versatile, he's unpredictable and he's reliable.

He's struck 19 goals in Holland and all of them have come inside the area. He averages an incredible amount of touches in the area (7.79) and Neres, to put it bluntly, just makes things happen.

The only real question mark hanging over his head is whether he'd be able to replicate his Eredivisie form in the Premier League.

Yes, Neres impressed for Ajax in the Champions League but those are, when broken down, isolated games. He'd be signed for his consistency and reliability.

It wouldn't be that much of a gamble for a Premier League side to spend £40million on him. It's by no means loose change but the market has changed. Liverpool helped change it with the signings of Alisson and Van Dijk.

It's the sort of fee clubs for an attacking squad player with an abundance of potential. Manchester City paid close to £30million for Gabriel Jesus and he wasn't tried or tested in Europe. Manchester United parted with £50million for Anthony Martial in a world before Neymar's record move to Paris Saint-Germain.

But would Ajax cash in on him this summer? It isn't like they need the money with cash coming in from their Champions League run and the sale of Frenkie De Jong. Matthijs De Ligt is expected to leave, too.

The offer for Neres would have to be a tempting one and above £40million you start to stray from potential and head into needing the player to be a guaranteed success.