The workings of a transfer are complicated; player and agent contact, coach contact, fee negotiation, alerting the media to the signing and much more.
However, sometimes, they are more complicated than they should be when the supposed selling club do not want to see their player leave which sometimes forces a player to go on strike.
This summer was no different as a number of big players went on strike as they tried to force a move to another club.
The Brazilian failed to move from Liverpool to Barcelona with the Reds rejecting three offers from the Catalans for the player.
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Barca have come out to say Jurgen Klopp's side wanted close to £180m for the midfielder who had even submitted a transfer request to the club.
2. Virgil Van Dijk
The Dutch defender was widely expected to quit the Saints for Liverpool but after selling three players the club was not willing to let another player leave.
The player has refused to train for the club since the beginning of pre-season and he looks to miss the first six months of the season.
He released a statement saying the club broke its promise to allow him leave this summer.
3. Diego Costa
The most high profile case of a player going on strike is Diego Costa who wants to leave Chelsea after being told by Antonio Conte at the end of last season that he would not be needed this season.
Latest report say the player who has not been in London since the end of last season is still in his hometown in Brazil.
4. Ousmane Dembele
He might have earned his move to Barcelona and become the second most expensive player ever but Dembele burned bridges doing that.
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The 20-year-old Frenchman refused to train and his former club Dortmund was forced to declare him wanted.
5. Davidson Sanchez
For starters, Davidson Sanchez is Tottenham's most expensive player ever after joining from Ajax this summer.
He initially went on strike at the beginning of the pre-season but later joined the club after he was told he would be allowed to leave if Spurs meet his valuation.
Mauricio Pochettino's side did that and he eventually move and reconciled with Ajax before moving to England.
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