The fastest way to improve a weakness in your team is to buy a player for that position. That's where transfers come in.
To be able to participate in transfers you must have finished the introduction and have a verified account
To see the list of transferable players you need to have a Scouting Office. If you don't have one, or can't find a player you want then you can also look for players in teams in your league or other leagues/countries. If you see a player you like you can approach it's owner to ask whether the player can be sold.
Note that you can only transfer players during the transfer windows. There is one transfer-window between the end of the season and the start of the next and another, shorter one, halfway during the season.
We find it important that the transfer market is used for fair sales and purchases of players for realistic prices. In particular it is not meant to transfer money between accounts or to help friends by passing them good players for an unreasonable price.
The rules for tansfers are directed to limit the possibilities for abuse. One of the consequences of this approach is that all transfered players have to pass through the open market. No agreed transfers or loans can be made and this is not something we can include in the future.
It is also not possible to pass a lot of (hidden) experience on a player you sell. You buy the player you see, when a player is sold a maximum of 5000 experience can be passed on to the new owner.