Federer has not played a Grand Slam since Wimbledon 2016.
Wawrinka won his first Grand Slam at 28.
This is Murray's first Grand Slam as world number one.
Wawrinka, the world number four, has a good head-to-head record against Murray.
By certain metrics, Novak Djokovic has had the better year.
The world number two is within touching distance of a second Wimbledon title.
He faces Roger Federer on Centre Court on Wednesday.
The 34-year-old withdrew from the French Open on Thursday.
The world No. 1 had a strange, desultory week at the Italian Open.
Novak Djokovic's coach didn't like the world number two casting doubt on the sport.
The British number one says his rival's theories are flawed.
Raymond Moore said that women should 'bow down' to Federer and Nadal..
The Spaniard eventually progressed to the quarter-finals.
Srdjan Djokovic has had a profound effect on the world No. 1's career.
The American is one major behind the retired star.
The Serbian world number one had a brilliant 2015.
Follow Andy Murray's progress through the Australian Open with our live television guide.
Rising British star's run ends at the semi-final stage in Melbourne as Serena Williams powers on.
Murray's father-in-law Nigel Sears collapsed during the British No. 1's round of 16 match.
Nick Lindahl admitted in court to using insider knowledge on a 2013 match for betting purposes.
Betting on an Australian Open mixed doubles match was suspended on Sunday prior to the game.
The 17-time Grand Slam winner admits the prospect of his children playing tennis is not exciting.
It was the 10th career major for Djokovic but only his second U.S. Open.
The two men arguably are the greatest rivalry in tennis.