We've already seen many surprising transfers this summer.
Millions have been splashed all over Europe to get the best players possible and with rich owners at clubs, no transfer seems improbable.
And investing in young talents for the future has been one of the major priorities for top European teams this summer.
So, let's have a look at the top five young players aged 21 or under who are on the shopping lists for many teams and could change clubs before the transfer window closes.
The 19-year old AS Roma centre-back was rock solid for the Giallorossi last season. Though they leaked goals galore, Marquinhos was the only saving grace that AS Roma could be thankful about.
His positional awareness, strong aerial prowess and a willingness to cary the ball into midfield belies his tender age.
Hence, it is not surprising that the likes of Barcelona, Paris Saint-Germain and Manchester United have lined up his door fighting for his signature. This, after just one successful season at Roma.
While many suggest he should remain at AS Roma for another season and hone his skills, only time will tell which option he chooses.
2. Lucas Digne
Another 19-year old defender who has been really impressive for his club last season. Lucas Digne, who plays as a left-back for Lille in Ligue 1, is one of the hottest properties in France and has been touted by many as a future superstar.
Lucas Digne was also a part of the French side which won the U20 World Cup recently.
Liverpool have been pursuing him for some time now, but Ligue 1 champions Paris Saint-Germain have also entered the race to sign the teenager. A move to a bigger club this summer looks certain for this wonderkid.
3. Erik Lamela
Just like his club team-mate Marquinhos, the 21-year old lanky Argentine has also been linked to a move away from Roma. Known for his exceptional dribbling ability and pace, Lamela played an important role for the Giallorossi last season in securing sixth place in Serie A.
He had an astonishing 15 goals and five assists to his name last season and AS Roma will find it difficult to keep hold of their young star, in case clubs decide to swoop in for him.
The likes Tottenham, Napoli and Liverpool have already been linked with him this summer, but with AS Roma strengthening their squad, it just might take more than just money for clubs to tempt him away from Rome.
A relatively unknown player, Bernard rose to prominence last season after a series of strong performances for his club Atletico Miniero. Under the tutelage of the magical Ronaldinho, the 20-year old Brazilian has improved a lot over the past year.
He was also a part of the Brazilian squad which won the Confederations Cup, which speaks volumes about his talent.
Tottenham have been strongly linked with Bernard all summer, but there is also interest from the likes of FC Porto.
While he can continue under the guidance of Ronaldinho for another year, the prospects of European football and better pay might just prove too hard to resist for the Brazilian.
5. Julian Draxler
This 19-year old German attacking midfielder plays for Schalke 04. With 13 goals and five assists to his name last season, he set the Bundesliga alight and is the latest in the line of talented German midfielders coming through.
Cutting inside from the left, he has the creativity to play killer through passes and also the guile and trickery to weave past defenders effortlessly.
Having been capped for his country four times, Draxler also has plenty of Champions League experience under his belt.
Although Schalke 04 have come out and said that he is not for sale, yet we have seen many bizarre things happen in the transfer window so far and a move away from the Veltins Area should not be counted as one.
The likes of Real Madrid, Arsenal and Chelsea have been courting him since a long time and a move to a team capable of challenging for League titles will be something which the German wonderkid would be looking for.
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