Career
He is coached by Mišo Đurić and Nikola Tomasović. Kolašinac was a finalist at the 2010 European Athletics Championships, where he placed ninth overall. He has competed for Serbia in indoor track and field events, including the 2010 IAAF World Indoor Championships and the 2011 European Athletics Indoor Championships.
He primarily uses the spin technique.
He improved his best to 20.64 m at the 2012 Gugl Indoor Meeting in Germany in February. In Olympic final he was placed 7th with a throw 20.71 m.
In addition to shot putting at personal best of 21.58 m outdoors (2091 m indoors), he has set a personal best throw of 63.18 m in the javelin.