The transfer window might be shut until the summer, but teams across Europe will now start sending their scouting teams on missions to make sure they are finding the best available talent around the world.
Every team wants a youngster in which they can develop and potentially sell-on for quadruple the amount they originally purchase them for some years down the line, and they will find those players scattered among Europe.
Here are five players, all 21 and under, who are going to be in hot demand in the next 12 months: 

France – Houssem Aouar, Lyon, central midfield

Relatively unknown to most of Europe, Houssem Aouar has been having his breakthrough season at Lyon with some immense performances in both Ligue 1 and the Europa League.Five European players Premier League teams should keep their eyes on Houssem Aouar
The French youth international is a typical central midfielder that loves to bombard forward. He might only be sleight in stature, but Aouar has incredible intelligence to know when the dribble is on and when he has to pick the pass at the right time. 
Aouar, like most young French players, has an incredible elegance in his dribbling that allures defenders into a false sense of security. One minute you see him, the next he is past you. Aouar successfully waltzes past his markers with ease. 
The 19 year old made his France U21 debut last November, but with the way his performances are going, it will not be too long until Didier Deschamps calls him up to the senior squad.
Everton will have been in awe of him when Lyon crushed the Toffees home and away, but there will also be other Premier League teams now closely watching his progression at Lyon. 

Italy – Lucas Torreira, Sampdoria, defensive midfield

Five European players Premier League teams should keep their eyes on Luca TorreriraOne of the most enjoyable players in Europe this season to watch has been Sampdoria’s Lucas Torreira. While he might not possess the dazzling speed of Neymar or Eden Hazard, his technical approach to the game, as well as his intelligence, is something to be admired.
Torreira, 21, has the heart of a lion in his native defensive midfield position, unafraid by any player that comes his way. The former Pescara midfielder might only be five-foot-five, but his presence is well known to those who try to cross him.
The Uruguayan has a similar tenacity to that of Paris Saint-Germain’s Marco Verratti - both are not particularly daunting physical players, but they have the aggression to win the ball back and are usually one step ahead of their counterparts. 
Torreira has made the joint fourth-most tackles in Serie A this season, averaging 2.8 per-game, and has been a stalwart of Sampdoria’s midfield. He is not afraid to get forward, either, but Torreira’s strengths are, by far, guarding his defence from penetrative attacks.
Napoli are rumoured to be incredibly keen on bringing him to the San Paolo, but English teams who need a combative midfielder should really be taking an interest in this exceptional talent.  

Germany – Leon Bailey, Bayer Leverkusen, left wing

Leon Bailey has been one of Europe’s hottest properties this season after finding the net eight times and recording five assists in the Bundesliga.Five European players Premier League teams should keep their eyes on Leon Bailey
What has set Bailey aside from his counterparts is his ability to create something from nothing and pure willingness to create moments of pure magic. Bailey has the ninth-most shots on target per 90 minutes in the league, which is quite remarkable given he plays on the wing and is up against centre forwards.
The Jamaican-born superstar has completed, on average, 2.1 dribbles per game, which makes him rank seventh in the Bundesliga. Bailey is showing incredible statistics for a player who is only 20 years old and has only just come onto the scene. 
There is no ceiling for Bailey in terms of how far he can go, and it is to no surprise that the likes of Chelsea and Liverpool are closely monitoring his situation at Leverkusen. 

Spain – Gonçalo Guedes, Valencia (on-loan from Paris Saint-Germain), left wing

Five European players Premier League teams should keep their eyes on Goncalo GuedesThe Paris Saint-Germain loanee has been a surprise at Valencia this season after impressing his critics on a consistent basis. Shipped out to Spain because of Neymar and Kylian Mbappé’s arrivals, Guedes has placed his hat into the ring as one of Europe’s finest young wingers.
The fully fledged Portuguese international has completed 2.2 dribbles per-90 minutes this season and has been one of Valencia’s best players in all competitions. 
Guedes’ main attribute is his close ball control and composure when being pressurised by onlooking defenders. It is a skill to fend off players with ease when dribbling, but Guedes has mastered it comfortably and looks incredibly elegant when gliding with the ball at the heart of his opponents’ defence. 
There are big things to come from 21 year old, but it will be no easy task in recruiting him away from Paris Saint-Germain after the season he is having. 

Netherlands – David Neres, Ajax, right wing

One of Europe’s brightest prospects and the future of Brazilian football has emerged at Ajax this season. Five European players Premier League teams should keep their eyes on David Neres
David Neres has consistently performed to an exceptional standard throughout this year’s Eredivisie and has contributed to 21 goals (nine goals, 12 assists) in 24 appearances.
The 20 year old has an immense future ahead of him but he is already making significant waves across world football with the performances he is showing. 
Neres has completed three dribbles per-game this season, the third highest in the Eredivisie, which is a phenomenal amount given his age and experience prior to this year. The Brazilian U20 star is incredibly quick-footed and has already been compared to Arjen Robben in the sense of cutting inside to strike the ball on his favoured left foot. 
If Neres can add the ability to go out-wide from time to time and vary his attacking game, then there is no reason why he cannot take Europe by storm and compete at a very high level in the Champions League.
English clubs have found it difficult to sign players from the Dutch league who excel in the Premier League, but Neres looks certain to take his game anywhere and excel. 

This blog was written for Soccer Box by Liam Canning. We specialise in official football merchandise for a huge variety of teams including Paris Saint-Germain and Ajax! Find your desired kit here.