Before each day's play at the 2020 Australian Open, we'll preview three must-see matches.
 Novak Djokovic vs.  Milos Raonic
“If anyone can give Djokovic some trouble here, it’s a big server like Raonic.” That’s how I originally wanted to start this preview. It makes sense, right? No one may be able to out-rally Djokovic in Melbourne, but a guy like Raonic might be able to eke out a couple of tiebreakers. The Canadian, after all, has been to the semis here, and he played well enough to take out Stefanos Tsitsipas in straight sets last week. Then, unfortunately, I looked at the Djokovic-Raonic head to head: Djokovic is 9-0, and has dropped just two sets in those nine matches. True, Raonic won one of those sets in their most recent match, in Cincinnati in 2018. But I don’t think we can say that he’s the most likely to give the seven-time Aussie champ any trouble. Right now, it’s hard to see who is.
 Ashleigh Barty vs.  Petra Kvitova
What would a tennis tournament be without a match between these two? The Australian and the Czech faced off five times in 2019 alone—Barty won three of them, Kvitova two. As far as Aussie fans are concerned, though, Kvitova won the two that counted, first in Sydney in three sets and then in the quarterfinals in Melbourne in two sets. Can Barty, who was just crowned the Young Australian of the Year (is it possible to imagine a similar award in the States?), surf the crowd support in Laver all the way to a revenge win? She won their last three meetings of 2019, including a straight-setter at the WTA Finals in October. But this is still a big ask. Kvitova nearly won the tournament here last year, and on Sunday she stormed back in convincing style after dropping the first to Maria Sakkari. Like Barty, she looked like she was on a mission.
 Roger Federer v. Tennys Sandgren
By now, there can’t be too many guys who Federer has never faced, especially those who are 28 years old and have been on tour for a decade. But Sandgren is one of them. Which of the two will be helped by the unfamiliarity factor? The 100th-ranked Sandgren, who started this tournament on Court 14 and hasn’t made it into Laver yet, may be a little overwhelmed to start. But anytime the Tennessean sinks his teeth into a match, he’s a threat to win it, and that should be true against Federer as well. Sandgren is ranked in triple digits at the moment, but he can rise to an occasion, especially Down Under. In 2018, he beat Dominic Thiem on his way to the quarterfinals here, and that same year he was the last man to take a set from Novak Djokovic at the US Open. That said, Federer appeared to have plenty of bounce left in his step against the similarly talented Marton Fucsovics on Sunday. He may not know Sandgren’s game, but he still knows how to play.