Federer booked his place in the semi-finals of the Australian 
Open after sweeping aside Tomas Berdych in straight sets.
Chung, meanwhile, 
has been the surprise package of the tournament so far.
After taking out Alexander Zverev and Djokovic, 
the South Korean reached the last four with 
a convincing win over Tennys Sandgren.
Chung represents an unknown quantity for
 Federer as the pair have never faced each other previously.
And Federer reckons Chung has a similar style 
to Djokovic especially in terms of being solid defensively.
              “I'll definitely have to look into
               how I need to play against him 
               because he has some great qualities, 
               especially defensively, like Novak has,"  Federer said.
                   "One thing I know is
               I'm going to be playing aggressive. 
               “I don't know how I'm going to do
                that exactly yet.