Uncoordination or athleticism problem?

im about 14 and i play a ton of basketball, im inthe middle of puberty and last yr i began to notice a lag in my upper body. mabe it was lack of coordination, but whenever i tried to do a crossover my upper body couldnt keep up with my legs and always went to the left a little before going to the right. it gets really annoying cuz my moves dont look smooth im wondering what could this problem be?