The summer transfer window only opened today yet there's already been some huge surprises since the end of the 2016/17 season.

For example, according to BBC Sport, Fabio Borini has joined AC Milan on an initial loan from Sunderland. He will sign permanently next summer.

This is despite the fact the Italian striker has scored just 15 league goals in the last five years, working out to a rather embarrassing three per season.

Elsewhere, Chelsea have completed the signing of free agent Willy Caballero, who was out of a contract following three years at Manchester City.

Chelsea needed a new back-up goalkeeper after Asmir Begovic joined Bournemouth, of course, but no one saw the Blues signing the ex-City goalkeeper.

Antonio Conte's decision to allow Nathan Ake to join Bournemouth for £20 million came as another shock, given the 22-year-old's potential.

However, all of these pale in comparison to what Wolverhampton Wanderers potentially have in store for this summer.

According to the Daily Mail, via Portuguese sources, Wolves have submitted an audacious - and that's an understatement! - £14 million bid for Porto's Ruben Neves.

Talks are underway between the two clubs and the Championship side are said to be confident of striking a deal. Wow.

In case you've forgotten, Neves is a highly-rated defensive midfielder and has been scouted by the likes of Chelsea, Manchester United and Liverpool.

He also holds the record as the Champions League's youngest ever captain, after wearing the armband for Porto aged 18 years and 221 days against Maccabi Tel Aviv in October 2015.

Neves' once meteoric rise has slowed down over the past year but if Wolves somehow manage to sign him, it would undoubtedly be the signing of the summer - in relative terms.

Indeed, it wouldn't be overly surprising if Arsenal, United or Liverpool decided to make a late move for the 20-year-old in light of Wolves' bid.

What's also interesting about this piece of transfer news is that Wolves, who were relegated from the Premier League five years ago, are dealing with one of the world's top agents: Jorge Mendes.

It's a bold move from ex-Porto manager Nuno Espirito Santo, who will only hope being Portuguese will aid his bid to sign one of his country's hottest talents.