Should i play linebacker or running back???????

MY COCH SAID THAT I HAD TO PICK ONE POSITION TO STAY ON HE SAID I HAD TWO CHOICES RUNNINGBACK OR LINEBACKER!!!!! HE SAID IF I DONT MAKE UP MY MIND BY MONDAY IL BE NO LONGER A STATER!!!!! SO I DONT KOW WHAT TO DO!!!!!! WHAT SHOULD I BE????????