Is it possible to be successful as a pitcher when?

I short arm the ball, when i throw my fastball i short arm it, but it has decent accuracy and 2 seam has good movement. and my curve drops alot, but can i be successful just short arming, my coach told me practice extending my arm, and i will but are there any major leauge pitchers who short arm and is decent, i can actually remember a pitcher who short arms their throw, i think he plays for the Athletics.