technically you're clearly hitting the right groove with these shots.
The "challenge" as I see it, is more what action that is going on (which you don't control).
These shots - good as they are - depict some pretty ordinary soccer-situations and there isn't anything in them that will make a soccer-fan go "ooh".
A more spectacular sport or an incredible persistence, patience and fast reaction time combined with endless hours of watching the ball through the viewfinder may yield more "spectacular" images.
Getting clear and well composed images (you have that already) of spectacular moments in the sport you are watching is a tricky combination of achieve and not all something you control. That's why the sports-photographers who cover soccer (and many other spots) take a gazillion shots, just to get that ONE killer shot for the front page of the sports section.
You seem to have everything you need to get great shots - only thing missing is 100's of hours doing it until something truly remarkable happens..lol.