The Croatian was the shock winner of the 2014 US Open when he defeated Kei Nishikori 6-3 6-3 6-3 and despite failing to reach those heights since, 2016 is about as close as he has been.
He beat Andy Murray to claim a maiden Masters 1000 title in Cincinnati and followed up with a semi-final in Paris later in the year - a round robin exit ended his second appearance at the World Tour Finals and if his serve is firing he poses a threat to the world's best.
A straight sets defeat to Roberto Bautista Agut in the third round was all he had to show for his 2016 Australian Open, while he suffered a first round defeat at Roland Garros.
A quarter-final appearance at Wimbledon was his Grand Slam high point but he threw away a two-set lead against Roger Federer before going on to suffer a third-round exit at the US Open. Cilic went out in the third round of the Australian Open before crashing out in his first match at the French.
Despite being on his favoured hardcourt Cilic has only one career appearance beyond the fourth round in Melbourne but that came back in 2010 when he was beaten in the last four by Murray,