slight scoring on inner disc surface

As per title, noted on MOT, I can feel slight scoring on the inner brake disc surfaces only.

Any ideas why this could be. Discs and pads only done about 3k miles and 1 track day.
 
could be a stone or something off the road surface flicked up between disc and pad mate

had this before when i just brought some ktr black edt grooved discs and ds2500 pads

so i stripped down the brakes and cleaned them up one afternoon and re assempbled them

since theyre new they will wear down under braking and should wear out the groove if its not deep
 
Thanks for the reply. The scoring is not just in one spot as if made by a stone, but seemingly across the pad contact area. Identicle on boths sides, which is weird and why I posted.