That is now possible (sort of!) thanks to Football Manager 2023 and their clauses section, where fans can see how deals are structured, although it must be stressed that some may not be fully accurate.
Football fans can delve into unrivalled depth and detail in FM 2023 as you take charge at your club. Join the elite by writing your own headlines, earning the love of the fans and dominating the competition. It's not just about picking tactics or crafting a team.
Here, we take a look at the interesting payment plans, buy-back deals and sell-on clauses inserted into the transfer contract of these current and former Sunderland players:
1. Dennis Cirkin
Tottenham have the option to buy Dennis Cirkin back for £6m. If the left-back moves elsewhere, 40% of his next transfer fee will be owed to Spurs. Sunderland also have to make three payments of £200k to Tottenham over the next two years as part of the deal according to Football Manager 2023. Photo: Frank Reid
2. Carl Winchester
25% of Shrewsbury Town loanee Carl Winchester's next transfer fee will be owed to former club Forest Green, according to the popular simulation game Football Manager 2023. Photo: Frank Reid
3. Aji Alese
25% of the profit made on aji Alese will be owed to former club West Ham, according to the popular simulation game Football Manager 2023. Sunderland also owe the Hammers three payments of £100k over the next three years. Photo: Frank Reid
4. Daniel Ballard
Arsenal will be due £2m if Sunderland gain promotion from the Championship before 30th June 2025. 40% of the profit on Ballard's next transfer fee will be owed to former club Arsenal, according to the popular simulation game Football Manager 2023. Sunderland also have three payments of £500k to complete over the next three years. Photo: Frank Reid