For the second summer in succession, Premier League clubs spent more money on transfer fees than every team from La Liga, Serie A, Bundesliga and Ligue 1 combined.A total outlay of just over €4billion (£3.4bn; $4.6bn) was driven by nine-figure deals for Morgan Rogers, Elliot Anderson and Enzo Fernandez towards the top of the food chain. Still, 16 of the 20 sides in the English top flight invested at least €100million (£86m; $116m) in their squads, highlighting the division’s growing strength in depth.Many of the game’s biggest names may only be heading one way, but that didn’t stop some of Europe’s shrewd operators making some intriguing signings away from the spotlight.As the dust settles on another hectic window, The Athletic’sThom Harris picks out 10 promising data-led signings who could be drawing the attention of the big spenders in years to come.*NB: All fees according to Transfermarkt, in Euros (€)Alvaro Rodriguez (22): Elche to Bournemouth (€25m; £21.5m; $29m)Though Bournemouth lost head coach Andoni Iraola at the start of the summer, their adventurous window suggests they are going to be no less ambitious without him.Alvaro Rodriguez is the latest of 18 players aged 23 or under to have joined the club for at least €10million in the last four years. Of that group, six players have been sold, including Antoine Semenyo, Dean Huijsen and Milos Kerkez, to generate over €160million in profit, while those who have remained at the club — among them Alex Scott, Rayan, Eli Junior Kroupi — have seen their valuations soar.Rodriguez is an eye-catching centre-forward who combines his 6ft 4in (193cm) frame with a silky first touch. Despite his height, he is an accomplished dribbler — only Kylian Mbappe completed more take-ons last season as a striker in La Liga — while he can gallop down the channels and bring others into play with neat flicks and lay-offs.All of those attributes combine to create a rare profile of striker, as shown by his pizza chart below — dominant in the air and with his back to goal, but also slinky and inventive with the ball at his feet. Here he is away to Rayo Vallecano, picking up the ball and gliding into a pocket of space. Rodriguez ducks away from the challenge before sliding a reverse pass through for Adria Pedrosa to strike at goal.Though it can sometimes look clumsy, it is the kind of slaloming run and clever pass we often see from Rodriguez. He also came up with some decisive moments in front of goal last season, scoring against Barcelona and Real Madrid for his relegation-threatened side.There are clear areas for refinement: Rodriguez is sometimes guilty of overplaying and can be too easily knocked off balance if the defender nudges him at full flow. But new head coach Marco Rose encourages his strikers to drop and link play, and Rodriguez offers a unique blend of skills for that role.Patrick Zabi (19): Stade de Reims to Paris FC (€25m; £21.5m; $29m)From one physical anomaly to another. Patrick Zabi uses his height (6ft 3in) to stride through midfield and blow games apart.Given his opportunity after Reims were relegated to the French second tier last season, Zabi played a variety of roles across the width of the pitch. He used his long strides to make more defensive recoveries per 90 minutes than any other team-mate last season, while also popping up with four assists and a sensational long-distance goal.Zabi’s most impressive trait, however, is his ability to drive forward with the ball at his feet. According to Opta, only two midfielders in Ligue 2 could better his rate of 7.9 progressive carries per 90, happy to drop into pockets of space before turning away from pressure and dragging his team up the pitch.We saw a glimpse of that during an impressive cameo for his new club in a 3-0 win over Nice. Just moments after coming on, he ambles out to the left, allowing the ball to roll towards him and encouraging the full-back on, before spinning down the touchline with a sharp turn on the outside.Zabi almost capped his 15-minute masterclass with a goal, nicking the ball deep inside his own half and running 60 yards with the ball, slotting his finish marginally wide.Though still with areas to grow, not least his decision-making under pressure, the potential for Zabi to develop into a commanding box-to-box midfielder is clear.Alessandro Circati (22): Parma to Benfica (€18m; £15.5m; $20.9m)Approaching his 23rd birthday, Alessandro Circati has already been through many of the highs and lows that professional football has to offer.Born in Parma to Italian parents, he moved to Australia and grew up in Perth, before returning to his hometown in 2021 to join the local side, where his father used to play. Three years later, he was the standout centre-back as Parma sealed their return to Serie A with the second-strongest defensive record in the division.All seemed to be going smoothly, until Circati tore his anterior cruciate ligament just five games into his maiden top-flight campaign. Remarkably, it took him just seven months to recover, immediately turning heads with his composure and tough tackling at the back.Last season, Circati started 31 league games on the right side of Carlos Cuesta’s stubborn 3-5-2 shape, the same position he held down throughout Australia’s run to the World Cup knockouts this summer. He is a reassuring presence in the defensive line, happy to chase runners into midfield but mature enough in his decision-making to ensure that he rarely overcommits.The graphic below illustrates that Circati is not a centre-back who sticks a foot in too often, preferring to sit off and protect the space. When he does go in for the ball, his ‘true’ tackle win percentage was the highest of any Serie A centre-back, while he made a number of crucial blocks and clearances closer to his own goal.In the wake of Antonio Silva’s move to the Premier League, Benfica should suit Circati, who is also comfortable moving the ball forward through adventurous carries and long passes from defence.Continental European football, and what should be a competitive tussle for the Portuguese title, is an exciting next step for a defender who seems to take everything in his stride.Haissem Hassan (24): Real Oviedo to Celtic (€7m; £6m; $8.1m)Those who caught Egypt’s stirring performance against defending champions Argentina at the World Cup this summer will have been drawn towards Haissem Hassan, the impossibly slippery winger who not once but twice scythed through Lionel Scaloni’s side.Here he is scurrying down the touchline in the build-up to a contentious disallowed goal, while he played a key role in Egypt’s second, skipping past Enzo Fernandez and pulling the ball back for Mostafa Ziko to smash home.It was a breakout performance for 24-year-old Hassan on the world stage, but the dancing winger has been breaking data models for a while. He attempted 7.3 take-ons per 90 minutes last season for relegated Real Oviedo — the 10th-most across Europe’s top five leagues — but his appetite for running at defenders begins to stand out further when placed in the context of his team-mates.As we can see from the scatter plot below, he was responsible for over a third of his team’s take-ons while he was on the pitch, while he ate up 26.2 per cent of the distance that Oviedo covered via carries, a magnet for mazy dribbles and zig-zagging runs whenever he played.Hassan has work to do in front of goal, having failed to score in almost 2,000 minutes on the pitch in La Liga, mustering only three assists. That said, his new side, Celtic, averaged almost double the number of touches in the attacking third per 90 minutes than Oviedo last season.Space will be reduced for him to run into, but it will be fascinating to see what Hassan can do with more opportunities to get at defenders, and whether his agility and natural dribbling ability will shine.Romano Schmid (26): Werder Bremen to Frosinone (€8.5m; £7.3m; $9.8m)Since Werder Bremen returned to the Bundesliga four seasons ago, Romano Schmid has quietly been one of the division’s most forward-thinking midfielders.No player has created more chances than the 26-year-old across that period, while he also leads the way for passes into the opposition penalty area. Last season, only Michael Olise generated more expected assists, an indication of the Austrian’s ability to move the ball into dangerous areas even if those passes were not always converted by a team-mate. As we can see below, Schmid’s influence is not limited to a single area of the pitch as he can swing in corners from both sides, thread through balls from either half-space and lay off plenty of neat link-up passes after ducking into dangerous areas on the edge of the box.Schmid is sometimes easy to barge off the ball, but makes up for his diminutive frame with great technique across the final third. He scored a stunning goal for Austria at the World Cup this summer, putting his laces right through a shot from 25 yards that nestled into the far corner against Jordan, while he repeatedly showed his ability to wriggle out of tight spaces with his low centre of gravity and quick feet under pressure.Promoted Frosinone have found themselves a creative leader at a bargain price.Lee Kang-in (25): PSG to Atletico Madrid (€35m; £30m; $40.5m)Though he struggled for game time throughout his three seasons at Paris Saint-Germain, Lee Kang-in often wasted little time showing what he is all about on the pitch.The 25-year-old is a zippy creative midfielder, with a wicked left foot for set pieces and driven shots from distance. He is always plugged into possession patterns and demanding the ball — only Ousmane Dembele and Khvicha Kvaratskhelia were involved in more sequences leading to shots per 90 minutes last season, while only Ballon d’Or winner Dembele could better his rate of 3.3 chances created per game.In addition to the punch he provides in the final third, Lee is hard-working without the ball, a talismanic figure at Mallorca in La Liga before his move to the French capital. He formed a productive partnership with target man Vedat Muriqi, constantly threatening with dipping crosses from deep, pressing from the front and helping to lead the line with adventurous runs in behind.