With the current economic climate likely to result in a significant change in how the transfer window functions, there is a chance a number of surprise deals could take place.

One side in particular that have been linked with a range of shock deals is Newcastle United, who are on the brink of being taken over by a Saudi-led consortium who look set to invest heavily in the North East club.

Some of the names mentioned include Napoli defender Kalidou Koulibaly, Lyon midfielder Houssem Aouar and Crystal Palace winger Wilfried Zaha, but perhaps the most surprising target is Real Madrid forward Gareth Bale.

Something of an outcast at Madrid under Zinedine Zidane, this is not the first time that Bale has been linked with a return to England, but were he to arrive at St James' Park it would surely be one of the most shocking deals ever seen.

With that in mind, here are 25 of the most surprising deals from around the world of football...

Robbie Keane to Inter Milan

After bursting onto the scene at Wolverhampton Wanderers and then Coventry City, Keane made a shock more to the San Siro. However, things did not work out and he only lasted six months before returning on loan to Leeds United.

Jerome Boateng to Manchester City

The German international arrived in Manchester early on in his career after a few seasons at Hamburg, but was never able to secure a spot in the first team. He left for Bayern Munich after one season where he finally found his best role.

Kim Kallstrom to Arsenal

With Arsenal's 2013-14 title bid faltering, Arsenal plumped for the Swede towards the end of the January window even though he was injured. His time in North London amounted to little, although he did score a penalty in a FA semi-final shootout win against Wigan Athletic.

Emmanuel Adebayor to Real Madrid

After falling out of favour at Manchester City, the Togo international secured a shock loan move to Real Madrid in January 2011. After managing eight goals in 22 matches, he returned to England to join Tottenham Hotspur.

Edgar Davids to Barnet

After a brief spell at Crystal Palace and then two years of retirement, Davids returned to join Barnet in League 2 as a player-manager. He remained at the club until 2014, when he resigned.

Alexandre Pato to Chelsea

After two years on loan at Sao Paulo, the Corinthians forward arrived in West London on a six month deal. The move did not really work out and managed just one goal in two appearances.

Javier Hernandez to Real Madrid

After a great start to life at Old Trafford, Chicharito fell out of favour in 2014 and was shipped out on loan to Real Madrid in January 2015 as a result. His spell at the Bernabeu was not too bad though, where he managed nine goals in all competitions.

Nicklas Bendtner to Juventus

After failing to make the grade at the Emirates, Bendtner made the surprise move on loan to Juve where he did not manage to score in 11 appearances.

Kyle Lafferty to Palermo

After making his name at Rangers, Lafferty spent a spell in Switzerland with Sion before joining Italian club Palermo. Despite scoring 12 goals from 36 appearances, his time in Serie B is best remembered for the club's owner describing him as a "out-of-control womaniser".

Sol Campbell to Notts County

After a successful spell at Portsmouth, the former England international moved to League 2 side Notts County in a shock deal. However, he left after just one match and returned to former club Arsenal.

Thomas Gravesen to Real Madrid

After an outstanding start to the 2004-05 season with Everton, the Dane made a surprise move to Real Madrid in the January of 2005. He would only last 18 months in the Spanish capital though before leaving for Celtic.

Steven Caulker to Liverpool

After an injury crisis hit the Liverpool squad, Jurgen Klopp moved for the Queens Park Rangers defender who had been on loan at Southampton, only to use him as a striker on his debut.

Esteban Cambiasso to Leicester City

After finally departing Inter Milan, the Argentine joined Nigel Pearson's Leicester City as they bid to secure their Premier League status. Cambiasso played a starring role that season but sadly left the summer before their famous title winning year.

Martin Braithwaite to Barcelona

With injuries hitting the Barcelona squad, the club were granted special dispensation to secure a move for Leganes forward and former Middlesbrough player Martin Braithwaite.

Andy Carroll to Liverpool

With Fernando Torres leaving Liverpool for Chelsea and Carroll impressing for Newcastle United, the Reds spent £35m on the England international in a move that never quite worked out. Carroll is now back at Newcastle although injuries have massively impacted his career.

Alex Song to Barcelona

In an era where Barcelona seemed to be signing every Arsenal player, they perhaps took it too far when the signed Alex Song. After a two-year spell on the sidelines, he returned to England on loan with West Ham United.

Michael Essien to Real Madrid

Despite injury resulting in his best form at Chelsea being behind him, Essien still joined Real Madrid in the summer of 2012. Luckily for him, he managed to stay fit and made 35 appearances in his one season at the club.

Henrik Larsson to Manchester United

After an incredibly successful career with Celtic and Barcelona, Larsson returned to Sweden in 2006 to rejoin Helsingborgs. However, six months later he joined Manchester United on a short term loan spell as the club chased  their first title since 2003.

Julien Faubert to Real Madrid

After a season and a half at West Ham United with limited success, Faubert earned a surprise loan move to the Bernabeu, but managed just two appearances before returning to East London.

Hidetoshi Nakata to Bolton Wanderers

After a very successful career in Italy, the Japanese international made a shock move to Bolton Wanderers in 2005. His move was not without success, with the side finishing eighth in the table and Nakata making 32 appearances overall.

Jonathan Woodgate to Real Madrid

After making his name at Leeds United before earning a move to Newcastle United, Real Madrid caused plenty of shock when they paid £13.4m for the defender. Injuries proved a huge obstacle and Woodgate made just 14 appearances.

Giuseppe Rossi to Newcastle United

Another player whose career was blighted by injuries, Rossi spent a short spell on loan in the North East prior to his move to Villarreal where he first made his name.

Tyrone Mears to Marseille

A player lacking top-flight experience when he made the move, Mears sealed a shock loan move to Marseille in the summer of 2008 after Derby County were relegated. However, he made just seven appearances before returning to Derby.

Steven Fletcher to Marseille

Another Brit who made his way to the south of France for no apparent reason, Fletcher joined Marseille from Sunderland in February 2016. He scored three times for the club before joining current side Sheffield Wednesday that summer.

Borja Valero to West Bromwich Albion

A player who has since made his name at Villarreal, Fiorentina and Inter Milan, Valero joined West Bromwich Albion in 2008 in something of a shock deal. He left on loan after one season before finally departing on a permanent basis in 2010.