Mats Wilander believes Nick Kyrgios has the capability of causing a 'big upset' in the Australian Open, but has raised concerns about the Aussie star's fitness. Kyrgios' first-round match against Jacob Fearnley next week will be his first match in a major tournament in over two years.

Nick Kyrgios faces another injury setback in his planned return to Grand Slam tennis at the Australian Open after an abdominal strain forced him to withdraw from an exhibition with Novak Djokovic this week.

Nick Kyrgios raised serious injury fears ahead of the Australian Open by pulling out of a planned charity match against Novak Djokovic. The former world No. 13 recently returned from a two-year injury layoff and has already suffered a new physical setback.