As the year 2006 ended last Sunday with Russia winning the Davis Cup, it's already time for the players and the fans to think about 2007.

The top players don't have much time to rest, as both year-end championships took place last month. Roger Federer and Justine Henin-Hardenne, the world number ones, will have to work hard in order to stay at the top. Here's what we have to look forward for the upcoming year.

Federer was by far the best player of the ATP Tour in 2006. By winning the Australian Open, Wimbledon and the US Open, his ninth Grand Slam crown, he can already think about surpassing Pete Sampras' record of 14 Grand Slam titles. He will also try in 2007 to emulate Bjorn Borg by winning a fifth consecutive Wimbledon trophy, something Pete never managed to achieve.

After winning the Shanghai Masters Cup, Federer is assured of remaining in  the number one spot at least until the spring hard-court season, but with the way things are going for him, he looks likely to stay there for a lot longer. Federer's main goal in 2007 will be to win all four majors in the same calendar year, thus becoming the third man to win the Grand Slam. But in order to do this he will have to win the one big trophy which has eluded him - Roland Garros. He came very close at the last French Open but lost out to world number two Rafael Nadal in the final.

Nadal had a bit of a letdown in 2006 after a fantastic 2005. Even though he dominated the clay-court scene with a second Roland Garros title, he failed to impress after reaching the Wimbledon final, which was an undoubtedly incredible achievement for him.

Fearless and mentally strong, Nadal will look to do improve in 2007 at the tournaments he missed in the past year through injury. He will also try to shine again on the dirt, even though Federer will be breathing down his neck. As in the 2006 Rome final, Nadal and Federer are clearly the two best clay courters and the pair will probably provide some more superb battles in 2007. 

David Nalbandian, Ivan Ljubicic, Tommy Robredo, Nikolay Davydenko, James Blake, Marat Safin and Andy Roddick are some of the players who could give trouble to the top two. Nalbandian, an all-court player, has reached the semi-finals in all the Grand Slams throughout his career. Ljubicic had his Grand Slam breakthrough at Roland Garros last year after reaching the semi-finals, Robredo will look to reach his first Grand Slam semi-final and Davydenko is twice a Grand Slam semi-finalist and a recent Masters-Series champion.

Blake and Roddick, the two top American players, will want to improve on clay and add some consistency to their game and Safin, probably the most talented of them all, will also be desperate to find his badly-lacking consistency. Perhaps winning the Davis Cup for Russia will help send some positive vibes through his system in 2007.

In the women's game, Henin-Hardenne will try to maintain her Grand Slam success which saw her reach four  finals in 2006 but she will have to be careful, as the two players chasing her are not far from claiming the number one spot. In 2007, she will simply have to go one better in the important tournaments where she lost in the final. Everything will start at the Australian Open, where things turned into a nightmare last year after she had to retire because of an upset stomach. She will also hope to stay away from injuries, something she was able to do for most of 2006.