Keeper training

[Tactician]

If you select only 2 GKs (and no other players) for a training session that involves a shooting drill, one of the GK will likely make gains related to saving shots (reflexes and so on), while the other might just waste his condition and make unwanted gains or no gains at all as he will be the one doing the shooting for the other GK to make the saves. Again, this is not a confirmed theory, but logic says it should be like this. A shared role could also be possible, where both GKs contribute to each part of this drill. You have to test and find out yourself.