Istomin knocked Djokovic out of the second round in 2016 in an epic five-set battle. Now, the Uzbek player is hoping to pull off a similar upset when he takes on Federer on Monday morning.
But the world No 3 has done his due diligence by watching the entirety of Istomin’s marathon clash with Djokovic.
Federer is the defending champion in Melbourne and is taking all necessary precautions to avoid being dumped out early.
“I know what Denis did to Novak,” Federer said. “I watched basically the entire game a couple of years ago when he beat Novak here.
“I’ve had some tough ones against him in the past. He can play well in fast courts, and that’s what it’s going to be a little bit here as well.
“Look, I’m playing good tennis. I’m confident that I think it needs a good performance by my opponent probably to beat me. That’s always a good thought.
“But then again, I think I’m playing well. Depending on how you match up with your opponent, who is going to win the big points, the margins are so slim nowadays that I’m just not thinking too far ahead.
“I don’t think I should because I think that would be a mistake. I hope I can put myself in contention as the tournament goes deeper, but we’ll see.”
Federer believes he has had the perfect preparation for the Australian Open after guiding Switzerland to back-to-back Hopman Cup titles. But he played down how well his ageing body is feeling.
“Well, I don’t want to overanalyse how I played in the off-season, how I played at the Hopman Cup,” he added.
“That’s exactly how then I might not recover if I have a bad start in the match tomorrow, let’s say. So I think the focus really is on those early rounds, especially tomorrow has to be.”