The Wimbledon Championships are just days away as the most anticipated fortnight of the tennis season gets set to begin.
With Rafael Nadal back in top form and Andy Murray recovered from a sore back, the Big Four are expected to dominate yet again. On the women's side, Serena Williams, who has won three of the past four Grand Slams, looks like the overwhelming favorite to win her sixth career Wimbledon crown.
But not so fast.
There are some lesser-known stars who could spoil the party for the Big Four and Serena in 2013.
Below we'll highlight a trio of dark-horse contenders to watch for in London this summer.
A 6'5" Canadian with a monster serve, Milos Raonic looks ready to challenge the big boys at the All England Club this summer.
At the moment, Raonic is struggling to transition from red clay to grass, losing back-to-back matches in Halle and Eastbourne as pointed out by The New York Times' Ben Rothenberg.
But expect Raonic to right the ship in time for the summer's biggest Slam.
Raonic has yet to reach a grass-court tournament final, but age 22 he's still adapting to the surface and should improve with time. This will be just his third year playing in the men's main draw at Wimbledon; he lost in the second round in each of his previous two tries.
In 2012, Raonic lost to American Sam Querrey in four sets in the second round, but three of those sets required a tiebreak.
With Raonic's serve becoming more and more deadly and this surface providing players like him with a huge advantage, it's only a matter of time before the world No. 15 figures it out and makes a deep run at Wimbledon.
He went 8-4 in Grand Slam matches last year and is 5-2 in major matches thus far in 2013. Therefore, look for Raonic to build on his recent successes at the All England Club this summer, battling past the second round and into uncharted territory.
Somehow, at age 35, Tommy Haas is playing his best tennis since the early 2000s. The German star has reached two ATP tournament finals in 2013, finishing as runner-up on the hard courts in San Jose before winning the BMW Open in Munich last month.
Heading into Wimbledon, Haas has momentum on his side after reaching the quarterfinals at the 2013 French Open; his best-ever finish at Roland Garros.
Although the All England Club hasn't been kind to Haas in recent years (he lost in the first round in 2011 and 2012), he reached the semifinals here in 2009 and has two grass-court titles to his name since June 2009.
Gearing up for his 14th trip to Wimbledon, Haas' experience is unrivaled. Plus, with his improved stamina giving him an added boost in a two-week tournament like this one, he has become a serious threat.
Another German who's always a threat on grass is 23-year-old women's star Sabine Lisicki.
Despite struggling to get past the first week at the other three Grand Slams throughout her career, Lisicki has blossomed at the All England Club, reaching the quarterfinals in three straight trips to SW19, including a semifinal appearance in 2011.
Lisicki's 13 career match wins at Wimbledon are as many as she has at the Australian Open and U.S. Open combined.
And what makes Lisicki so dangerous on the fast-playing grass is her ability to be aggressive and dictate points. She routinely plays from the baseline, striking powerful, heavy balls with challenging topspin.
Like so many other contenders at this Slam, her big serve is also a deadly weapon and has been key for her deep runs in the past.
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