problem with my player skill point gain

[Midori Ichi-nichi]

Can anyone explain me why my youngest player (name Fomenko, ST, quality 35,5 star at lv4, age 19, market value 1.66m, season wage 78k) always get the lowest skill point gain after either training or playing match.
Example: after streching,

[Cat Harrison]

here's a fast trainer at your level:

he likely was a youth from several levels above you, the above was a generated player, and one of the fastest you would find.