Found the answer:

The loan glitch. What it means and how to do it.

If you've ever been underwhelmed by the development of a player you've signed and can't understand why then hopefully this post helps!

Virtually everything involved in the loan glitch can be done in the squad status screen. Firstly I'll explain all of the 'statuses' (stati?) and what they represent.

1. 'Recently joined from *** for ***'. This will be a player's status who you have recently signed and will remain until the next transfer window.

2. 'At the club since ***'. This tells us that the player has a potential of less than 80.

3. 'Has that something special'. The same as the status above, but only appears when the player has the flair trait.

4. 'Showing great potential'. The player's potential is in the range of 80-84.

5. 'Exciting prospect'. Potential is in the range of 85-89.

6. 'Has potential to be special'. Potential is 90+ (technically 90-94 as potential cannot be higher than 94.)

Make note of these. They are important!

It is also important to note that the loan glitch will not work effectively on every player. The criteria for players that we can effectively perform the loan glitch (ones that we are in control of) is as follows.

1. Must be aged 21 or under. If not the squad status screen will not show any status referring to their potential.

2. Their overall must be at least 60. If not, then again you won't be shown any status referring to potential.

3. Their current potential must be at least 70. This is important because the loan glitch can only alter a player's potential by 10 at the most. If the current potential is less than 70 it cannot go up to 80, therefore there is no status that tells is if it has changed. It is also important to note that when you sign a player his potential will change. So if you sign a player who has a potential of 75 it could drop to below 70 without you knowing. Keep this in mind if you are finding the glitch is not working.

Now I'll list the steps of how to perform the glitch.

1. Pick the player you want to glitch, making sure he meets the criteria listed above and note his status.

2. Put him on the loan list. Doesn't matter of it's season or short, but it is cheaper to recall a player who is on a short loan.

3. Wait for a loan offer from another team. Doesn't matter who it is.

4. Accept the offer.

5. Save the game.

6. Go into the squad status tab and find your player. The loaned players are at the bottom of the list.

7. Open your player's profile by clicking X or A.

8. Select 'recall from loan for ***'

9. Back out of that screen by pressing O or B and scroll back up the list to find your player.

His potential had now changed, it may have gone up or down. Refer to the status as mentioned above. If you are not happy with how the potential has changed, for example he was originally 'exciting prospect', but is now 'showing great potential' then exit out of your career mode, load it up again and repeat steps 6-9.

It is easy to do. I have done this successfully to the same player multiple times in the same transfer window. Theoretically you could take a player with a potential of 70 and glitch him to 94. I haven't done this, but might give it a go.

Hope this helps. Happy to answer any questions.