After paying another Football Club certain fees to obtain a Player as a transfer in Football Manager 2018, you may ultimately look to sign said player should they perform better than expected. Unfortunately, you won't be able to do so since the rights for this individual still belong to the other Football Club. However, there are a number of things you can try to do in hopes of getting said other club to eventually sell the player to your team.
Unlike previous versions of Football Manager, Football Manager 2018 includes a number of brand new Transfer and Contract Clauses. Because of them, you can make great use of the new installment options included in such in order to comply with the Financial Fair Play, making sure another club that is loaning you a Player on a transfer gets paid their fees accordingly. By keeping up with your fees, you will stay within good standing with the other teams your doing business with in the form of transfers.
On top of this, you can even give other financial incentives to other Football Clubs you have transfer deals with, such as sending them bonus Money should said Players win some silverware while at your club. It might not seem like much, but sweetening the pot for another team could be enough to allow them to sell a transfer to your team. If you truly want to obtain the rights on a Player that did incredibly well with your team while on a transfer, there is nothing you shouldn't do in order to try to obtain them.