Australian former tennis player and coach Marinko Matosevic has been handed a four-year ban after breaching anti-doping rules. Matosevic, 40, reached a career-high singles ranking of 39 in 2013. He retired from the sport in 2018 and has since become a coach, working with Australian players Chris O'Connell and Jordan Thompson. "An independent tribunal determined that Matosevic committed five anti-doping rule violations between 2018 and 2020," the International Tennis Integrity Agency (ITIA) said in a statement. "Including use of a prohibited mthod through blood doping (while an active player) and facilitating another player to blood dope, providing advice to other players on how to avoid positive tests, and use and possession of the prohibited substance clenbuterol." There is no suggestion O'Connell or Thompson have breached any rules. In a statement published by Australian tennis website The First Serve in February, Matosevic admitted he underwent a blood transfusion in Morelos, Mexico towards the end of his playing career.