Power Rankings: Clay-to-grass transition no easy matter

The brevity of the grass-court season, arriving straight after the physically taxing European clay swing, creates an ongoing dilemma for tennis' leading players. Given the stark differences between the two surfaces, it is widely accepted that getting some matches on grass under your belt is the way to go.

But where, and, more to the point - when? With only two weeks separating the end of the French Open and the start of Wimbledon, choices are limited.

Few men with ambitions of going deep into the draw at Wimbledon see much merit in playing a warm-up tournament at Eastbourne or Den Bosch which ends just hours before the first eager patrons start queuing on the sidewalks outside the All England Club.

That is why, for the past several years, Rafael Nadal played at Queen's just a couple of days after winning the French and Roger Federer has trekked to Halle in Germany with regularity. Both those players missed their warm-up events this year, Nadal through injury and Federer because of weariness, potentially leaving them undercooked for the biggest tournament of the year.

Nadal has undertaken to play an exhibition at the Hurlingham Club a few days prior to the championships. Federer's plans are unclear at this stage.

Andy Murray played, and won, at Queen's, giving him five matches worth of positive tune-up and now a week of private preparation. Novak Djokovic also got the kind of match play he wanted, reaching the final in Halle before losing to Tommy Haas.

For the women, the approach is somewhat different. Without the concern of best-of-five-set matches at Wimbledon, many leading players have no problem with playing a tournament this week.

Dinara Safina is in action in Holland and Maria Sharapova will play back-to-back weeks after competing in Birmingham.

The goal of being fit and ready but still fresh for Wimbledon is far from an exact science, but is a challenge that can have a huge bearing on the greatest tournament of them all.

Here we take a look at the latest edition of the Yahoo! Sports Power Rankings, with few changes from last week because of the inactivity of most players. The previous week's rankings are noted in parentheses:

MEN

1. (1) Roger Federer: Missed Halle but a big favorite to regain Wimbledon

2. (3) Andy Murray: Brit will aim to defy history by winning on home soil

3. (2) Rafael Nadal: Huge concern over knee problem drops him a place

4. (6) Novak Djokovic: Can be a threat on grass when he is in top form

5. (4) Juan Martin Del Potro: Hoping to continue recent momentum

6. (5) Fernando Gonzalez: Putting together an impressive and consistent year

7. (7) Robin Soderling: Wants to maximize his French Open breakthrough

8. (-) Gael Monfils: Has worked hard to get ready for an improved showing on grass

WOMEN

1. (1) Dinara Safina: Not a big fan of grass but is desperate to make her mark

2. (2) Serena Williams: Health issues continue to cloud her chances of victory

3. (3) Svetlana Kuznetsova: French Open champion is feeling strong and confident

4. (4) Venus Williams: Wimbledon specialist will be looking to add yet another title

5. (6) Maria Sharapova: Hurriedly returning to form and fitness - just in time

6. (5) Victoria Azarenka: Doubts remain over her ability to adapt to an unfamiliar surface

7. (7) Caroline Wozniacki: Has all the tools to reach the top but needs more belief

8. (8) Elena Dementieva: Urgently needs to get her season back on track