Federer is considered a huge favorite according to the betting odds (i.e. bet365 has him at 1.5 to win straight up), however Tomic will be playing in front of an energetic home crowd.
The 19-year-old Aussie is a resilient player who came back from two sets down in the first round against Fernando Verdasco. Tomic could be more in the match against Federer than what is generally assumed, as the Aussie's confidence has to be improving.
In a five-set, third-round match, Tomic defeated Alexandr Dolgopolov, a player who made the quarters at last year's Australian Open. It was not an easy victory by any stretch, however Dolgo is a dangerous player when he is playing well.
Federer and Tomic have met just the one time before in a match that took place under somewhat similar conditions. They met in 2011, and although that match was not a Grand Slam contest it was still a Davis Cup match.
That made their previous encounter a best-of-five-set match and, like Saturday's match, their previous match was played in Australia.
Federer won that match three sets to one on grass, although Tomic has improved since their one and only meeting as he continues to move up in the rankings.
Federer and Tomic are scheduled for the first match in the evening session from Melbourne Park on Day 7. The start time for the match is 7 p.m. Melbourne time in what has the potential to be a classic.
Tomic, with a win, would make huge headlines and he would assert himself as a Grand Slam force.