- after the last update about training and skills, white and grey skills don't have any difference in gaining
- a manager who has a mutant players 5* (with 340%/1% - or something like this) don't want to improve his quality anymore.
There is no reason to play friendlies.
new players can not be trained to make full 340/1 so managers use friendly matches to achieve this goal (in which case there is no need to use upseling)