Milos Raonic's serve and ability to keep his nerve make him a threat. (Jonathan Nackstrand/AFP/Getty Images)
We've previewed the top men and women who should make a splash in the Australian Open, but what about the next tier of players who, whether because of recent form or a favorable draw, could shake things up? Here's a look at five men and women to keep an eye on as the tournament starts Monday in Melbourne (7 p.m. ET Sunday).
Milos Raonic: "Under the radar" is fast becoming an outdated way to describe Raonic, one of the ATP's rising stars. The 21-year-old Canadian has already won a title in 2012, the Chennai Open, where he wasn't broken once in four matches and defeated top 10 players Nicolas Almagro and Janko Tipsarevic. His powerful serve-and-volley game is impressive, of course, but what really stands out to me the most about Raonic is his steely nerve, which indicates a maturity that belies his youth. When Raonic loses, it's not because he gets nervous or chokes; he just flat out gets beat. That may seem like odd praise, but nerves can play such a big role in wins and losses. The 23rd-seeded Raonic could see Andy Roddick in the third round and Novak Djokovic in the fourth.
Bruce Jenkins: Raonic the hottest young player in tennis
Bernard Tomic: The 19-year-old unseeded Aussie's draw isn't easy, as he opens against Fernando Verdasco on Monday and could meet the tricky Alexandr Dolgopolov in the third round. But Tomic loves the big stage, with the spotlight bringing out the best in him. He made the quarterfinals at Wimbledon last year and put in memorable performances in Melbourne the last two years. His face is going to be plastered all over Australia if he gets on a roll here, as it should. He's Australia's next great hope.
Marcos Baghdatis: It never truly feels like the Australian Open until Baghdatis is kissing the court, which he does in front of his boisterous Cypriot fans after victories. The 2006 runner-up has a good track record here and he's always game for some drama. He scored an impressive straight-sets win over Juan Martin Del Potro on Thursday in Sydney. The unseeded 26-year-old has been blessed with a relatively cushy section of the draw that is anchored by No. 10 Almagro and 21st-seeded Stanislas Wawrinka, both of whom have struggled. If Baghdatis gets on a run, he could see Rafael Nadal in the quarterfinals. Put that one on Rod Laver Arena and start it after 10 p.m. and we could see something special.
John Isner: Whether it happens this year, next year or the year after that, it's only a matter of time before Isner becomes the new American No. 1. (The 17th-ranked Isner trails No. 8 Mardy Fish and No. 16 Roddick.) He has a difficult draw, with a potential second-round match against David Nalbandian or Jarkko Nieminen (who is in Sunday's Sydney final) and then possibly Feliciano Lopez in the third round. But if he can survive those matches, the 26-year-old Isner could get Nadal in the fourth round. He pushed the Spaniard to five sets on the Roland Garros clay last year.
Kei Nishikori: The 22-year-old from Japan surged at the end of 2011, making the Shanghai semifinals and upsetting Djokovic to advance to the Basel final (where he lost to Roger Federer). Seeded 24th, he has a nice early draw. He'll play no one ranked higher than No. 97 in his first two rounds, and he'd definitely have a chance against 12th-seeded Gilles Simon in the third.
Maria Kirilenko has been making more of an effort to get to net, where she has nice touch. (Zumapress)
Anastasia Pavlyuchenkova: "Pavs," a two-time Grand Slam quarterfinalist last year (French Open and U.S. Open), seems destined for an even better result at some point. When the 20-year-old is hitting the ball crisply and moving well, she can blast almost anyone off the court. Making the quarterfinals here as the No. 15 seed would mean potentially getting past Petra Kvitova, who split two three-set matches against the Russian last year.
Maria Kirilenko: She's not just a pretty face. The No. 27 seed went a long way in proving that she's one of the more feared players in any draw last year, when she began shedding her baseline-bashing ways and embracing the skills that have made her one of the top doubles players: net play. Kirilenko has phenomenal touch at the net and is at her best when she commits to attacking her groundstrokes with an eye toward moving forward. I'm really looking forward to her projected clash with Kvitova in the third round. If that's played under the searing Melbourne sun, I smell an upset.
Kaia Kanepi: Kanepi may not be a household name, but she's already made the quarterfinals at the other three Slams (she hasn't been past the third round in Melbourne). The talented Estonian, 26, has been hampered by injury through much of her career, but she looked fit and on form on her way to the title in Brisbane earlier this month, knocking off Pavlyuchenkova, Andrea Petkovic, Francesca Schiavone and Daniela Hantuchova. Now let's see whether the No. 25 seed can keep it up, with Vera Zvonareva potentially looming in the third round and Serena Williams in the fourth.
SI.com Roundtable: Kanepi among the dark horses to watch
Zheng Jie: On the heels of her title in Auckland (and her star turn in this video), there is reason to believe that Zheng might be back on track after being derailed by wrist surgery. A two-time Grand Slam semifinalist, including in Melbourne in 2010, Zheng's flat hitting causes a lot of problems for the top players. She's been drawn into Kvitova's quarter, but the good news is that she's in the 1/8 led by Samantha Stosur and Marion Bartoli, two players coming in with erratic form.