However, the pair may be required to pay in excess of what they deem an appropriate fee due to a sell-on clause included in Raphinha's contract according to Rennes executive director Olivier Cloarec.
"Yes, there are bonuses that continue throughout their contract and, possibly, if there are transfers from the current club to other clubs."
"Yes, it is in the millions,” he said to TVR, when pressed on the value of the sell-on clauses, as quoted by FootMercato.
Cloarec also referenced former Rennes midfielder Eduardo Camavinga's move to Real Madrid, but the decision to list Raphinha's Leeds switch alongside the €40m Madrid transfer suggests the add-ons owed to the French club could be significant.
For that reason, Leeds are more likely to drive a harder bargain in the transfer market this summer, aiming to recoup as much as they can from any prospective Raphinha sale before fulfilling their obligation to the Ligue 1 outfit.
Raphinha is valued at over £50 million by Leeds, while reports in Spain claim Barcelona are only willing to pay between €40m and €45m for the Brazil international's services.
To date, Arsenal are the only club to have tested United's resolve by lodging a bid earlier this week.
Elland Road chiefs swiftly rejected the Gunners' speculative approach, deeming their offer too low to even consider.
That said, Arsenal are expected to return with an improved offer given the north London club are on the offensive in the transfer market.
They have already committed to around £40 million in transfer expenditure this summer with the arrival of Fabio Vieira and Matt Turner, meanwhile Mikel Arteta's side also remain front-runners for Manchester City forward Gabriel Jesus, who is likely to be usurped at the Etihad Stadium by new addition Erling Haaland.
The exact percentage of Raphinha's sell-on clause has not been disclosed but considering the price Leeds are likely to deem suitable, Rennes are expected to receive millions.
There is also the matter of a small solidarity payment reportedly owed to Raphinha's first club Avai in his native Brazil, which is common in international transfers as a form of compensation for having initially trained the player.
This fee was initially reported by Brazilian sources six months ago when it was incorrectly claimed Raphinha had agreed a deal with Bayern Munich.