Release clauses, buy-back options and sell-on agreements are all standard parts of a modern-day football contract.
But every so often some truly baffling stipulations are squeezed into the small print of deals handed out by the Premier League’s most elite clubs.
Alex Oxlade-Chamberlain famously had a clause in his Arsenal deal that meant the Gunners would have to pay his former club Southampton £10,000 every time he played 20 minutes or more.
Meanwhile, Barcelona have inserted €1billion (£846million) release clauses into Ansu Fati and Pedri’s contract extensions to discourage any potential bidders for the two teenage wonderkids.
And from a financial perspective, those agreements make all the sense in the world compared to the likes of Ronaldinho’s nightclub request.
With the January transfer window set to slam shut on Monday, some more odd requests could be made as clubs look to push through late deals.
Here, talkSPORT.com takes a look at the 10 weirdest contract clauses in football…
Cardiff City’s eccentric former owner Sam Hamman was renowned for the unique clauses he added into his players contracts.
And none more so than Prior’s signing from Manchester City was conditional on him eating sheep’s testicles – a delicacy in Hamman’s homeland Lebanon.
He said: “It must be the strangest contract in the history of football. But I’ll try anything once.”
Prior did indeed eat the dish with a pinch of salt, lemon and a little parsley… before it was later revealed that he was in fact served slow-cooked chicken!
The former Arsenal player was committed to signing up for one of the first commercial flights to space when he joined Sunderland from Valencia in 1999.
However, the Black Cats were less keen on this idea and inserted a clause in Schwarz’s contract that would nullify his deal should he leave the planet.
Sunderland’s then-chief executive, John Fickling, said: “One of Schwarz’s advisers has, indeed, got one of the places on the commercial flights.
“And we were worried that he may wish to take Stefan along with him. So we thought we’d better get things tied up now rather than at the time of the flight.”
The German thought he was onto a winner when he told Arminia Bielefeld to build him a house for every year of his deal when he signed in 1996.
The club agreed to his demands but made sure to take Reina at his word as he never specified the size or type of property he wanted every season.
Bielefeld ended up building a house for their new striker out of LEGO for each year of his three-year contract – not the best way to keep him happy but funny nonetheless.
A lot of footballers are looking out for their family’s best interests when signing a new deal with a club but Guie-Mien took it one step further.
The Congolese international instructed Eintracht Frankfurt to arrange cooking classes for his wife as part of his deal to join them in 1999.
The midfielder was insistent that his other-half’s improved culinary skills would help him settle into German football better.
The Arsenal legend earned the nickname ‘Non-Flying Dutchman’ during his time in north London for his clause preventing aeroplane travel.
Bergkamp first publicly admitted his fear of flying during his debut campaign at the Gunners, with the decision costing him £100,000 in pay.
The Ajax icon chose to travel by train or other modes of transport wherever possible and missed many away European games as a result.
He elaborated on his fear in his autobiography, revealing that his experience of small planes at Inter Milan was the main reason behind his phobia.
The mercurial Uruguayan’s past behaviour caused Barcelona to add in a ‘no biting’ clause when he they agreed a deal to sign the striker from Liverpool.
Suarez was already banned when he arrived at the Nou Camp in 2014 for taking a chomp out of Giorgio Chiellini during the World Cup that summer.
He also took bites out of PSV Eindhoven star Otman Bakkal and Chelsea defender Branislav Ivanovic during his time at Ajax and Liverpool respectively.
Ex-Barca president Josep Maria Bartomeu denied the existence of a clause at the time but he has since been accused of lying about the club’s financial state by his successor Joan Laporta.
The enigmatic Italian also necessitated the inclusion of contract clauses surrounding his bad behaviour – in a deal involving Suarez!
Balotelli was earmarked as the man Liverpool trusted to replace the Premier League’s top scorer in 2014 after AC Milan had decided to offload him.
But the Reds had concerns about Super Mario following stories of throwing darts at people and nearly burning his house down with fireworks.
Therefore, Liverpool put a good conduct clause in his contract stating that he’d have to leave the club if he stepped out of line.
The Liverpool trifecta finishes with the Brazilian forward in a transfer once again put in motion by Atletico Madrid striker Suarez.
Reds owner John W Henry was incensed by Arsenal’s infamous £40million + £1 bid to poach the now-34-year-old from Anfield in 2013.
And the billionaire American was clearly still smarting at the attempt two years later when Liverpool agreed a deal to sign Firmino from Hoffenheim.
The 30-year-old’s contract with the Merseysiders carried a €98million (£82.5m) release clause ‘if the interested club is not Arsenal’.
The former Ballon d’Or winner was an exception to a standard nightclub clause in his contract – in that his allowed him to continue partying.
Far from encouraging Ronaldinho to not go clubbing and focus on his football, the Brazil icon had a different agenda when he left AC Milan in 2011.
The 41-year-old had Flamengo stipulate in his contract that he was allowed to hit the town twice a week without getting a fine or other repercussions.
Crystal Palace had a desperate measure to ensure ‘Razor’ was in shape when he arrived a Selhurst Park towards the end of his career.
Ex-Eagles chairman Simon Jordan wrote in his autobiography: “On approaching West Ham I discovered he was a free transfer, although he did have a weighty salary — which was not the only weighty thing about him.
“Harry Redknapp, the West Ham manager at the time, told me to put in a weight clause.
“So I decided to put a 10 per cent penalty on the contract we were proposing to offer him if he was over the recommended weight of 99.8kg, which by the way was still frigging huge.”