MARANA, Arizona, Feb 24 (Reuters) - The PGA Tour says it will announce a decision "relatively soon" following the admission by former world number one Vijay Singh that he had been using deer antler spray, which contains a banned substance. Fijian Singh, a three-times major winner, told Sports Illustrated magazine he had experimented with deer antler spray for "a couple of months" but was unaware the extract contained an insulin-like growth factor banned by the PGA Tour. ... More...