The transfer window has been open for six days and already it is hotting up ahead of what promises to be a long summer of transfer action across Europe.

Each morning, Football Whispers pore over Europe’s major transfer news outlets in search of the latest reports relating to your club.

We then assess the reliability of the rumours, determine the likelihood of the moves, and analyse where the potential signings would fit in.

Today, the transfer rumours around Europe focus on Chelsea striker Diego Costa, Fiorentina's Federico Bernardeschi and Schalke's Leon Goretzka.

Diego Costa set for Atlético Madrid return

The Costa saga looked set to be one which would run and run. However, mercifully, it appears to already be over with an emotional return to Atlético Madrid set to be confirmed as early as today.

Costa, who scored 20 times as Chelsea won the Premier League last season, has been hankering for a move since a reported offer from the Chinese Super League in January.

Blues boss Antonio Conte managed to placate the combustible Spaniard but Costa was not the same player in the second half of the season and a parting of the ways was inevitable this summer.

Conte did his bit to ensure that would happen, texting Costa while on international duty with Spain to explain he would not be part of his plans this coming season.

Talk of a mega-bucks move to China is still in the background but, according to AS, Costa will re-join the club he won La Liga with in 2014. Atleti can't register any new signings until January, owing to their transfer ban, but a loan move to the CSL would keep Costa sharp until then.

Given Costa's ties with Atleti and the relationship he had with Los Rojiblancos coach Diego Simeone, a return to Spain would be attractive and keep the striker playing at the highest level of European football.

Juventus won't meet Bernardeschi price

Having won six Serie A titles in a row, refreshing his Juventus squad is an important to Bianconeri coach Max Allegri as retaining Chelsea transfer target Alex Sandro.

According to Gazzetta dello Sport, the former Milan boss has identified Fiorentina's exciting younger winger Bernardeschi as the man to add a new dimension to his Juve side for next season.

Fiorentina winger Federico Bernardeschi's 2016/17 Serie A statsLa Viola have set a €50million (£43.8million) asking price for the 23-year-old who scored 11 goals and supplied four assists for the Florence outfit last season. However, Juve are only prepared to offer €40million (£35.1million) to sign the Italian international.

The reality in Italy, where the Old Lady have dominated for so long under Conte and now Allegri, is Juventus usually get what they want. Their pursuits of Gonzalo Higuaín and Miralem Pjanić were very public and drawn out but eventually a deal happened.

Given Juve are keen to offload former Fiorentina wideman Juan Cuadrado, who they were obligated to sign for €20million after winning Serie A, could the Colombian could be used a makeweight in a deal for Bernardeschi?

Bayern Munich face Goretzka tussle

Much like Juventus, Bayern are used to getting their own way domestically. It's why they have been able to sign Mario Götze, Mats Hummels and Robert Lewandowski from Borussia Dortmund in recent memory.

And the Bavarian giants are keen to take Schalke midfielder Goretzka, previously reported as a Liverpool transfer target, this summer.

The 22-year-old, who has just helped Germany reach the final of the European Under-21 Championship, scored five and assisted three in the Bundesliga last season.

However, according to Bild, Champions League and La Liga winners Real Madrid are also interested in signing the classy midfielder who is out of contract next summer.

That means that if Schalke want to pick up a transfer fee for Goretzka their best chance to do so is this summer and a transfer tussle will only ramp up the price.

What will play into Bayern's hands, however, is that Real are also keen to get a deal done for Real Betis' precocious midfielder Dani Ceballos. If the Spanish Under-21 international moves to the Bernabéu, Los Blancos might not be so keen to do a deal for Goretzka.