Former Aussie pro Grant Doyle tweeted today that he will not be working with young American gun Ryan Harrison during the 2013 ATP season. Harrison is listed among the Advantage Doyle charges on the coach's website, but that is sure to change soon enough. Doyle began working with Harrison as of a December 2011 announcement.
This marks four coaches with whom the 20-year-old has worked and then parted in the past 20 months. It's true that Harrison is young, and monitoring his next coach-player relationship should speak volumes to his development, to his next-step aspirations. It remains that he is seeking a breakthrough, an ATP tournament final appearance or a top-flight upset victory.