Can players increase skills?

Hi all,

I m looking at this player database which is very useful:
swos.gazchap.com/index.php?region=3 league=9 teamid=313

I know players can increase their value if they play in the right places, but can they also increase their skills?
I mean, if a player is 5 in Speed, will it become 6 eventually?

PS: I m playing the XBOX Live version and playing in Career mode.

Thanks

Thanks for your reply!