Wimbledon talking points: Serena Williams' seeding saga and is Roger Federer fallible?

Wimbledon organisers decided last week to name seven-time champion Serena Williams as the 25th seed , despite the American being ranked No 181 following her lengthy break from tennis to give birth to her first child. The decision has been met with both support and criticism: those in favour point to Williams' past achievements at Wimbledon and insist she should not be punished for taking time out to have a baby. Critics, including world No 32 Dominika Cibulkova who lost out on a seeding because of Williams, believe it punishes those who have worked hard in her absence. While Williams has nothing to prove at Wimbledon - or indeed at any tennis event anywhere in the world - the pressure is on to prove the decision was right. It's difficult to forecast how the former world No 1 will fare. On one hand, Williams is desperately short of match fitness having played just three tournaments this season - amounting to a grand total of seven matches. On the other, it's Serena Williams at Wimbledon. Either way, tennis fans will be delighted to see her back in action. ___________ Read more: Predictions: Will anyone stop Federer and Muguruza from retaining their titles? Roger Federer backs himself and Rafael Nadal as 'the big favourites' for Wimbledon ___________ Garbine Muguruza is a curious player. Arguably the most talented player on the WTA Tour, the Spanish world No 3 continues to struggle for the consistency her abilities deserve. But there is no question Muguruza raises her game, seemingly out of nowhere, in time for the grand slams. She won Wimbledon last year after losing 6-1, 6-0 in the second round of Eastbourne. In 2016, her French Open success was preceded by early defeats in Stuttgart and Madrid, although a semi-final run in Rome offered more encouragement. So how has she prepared for her Wimbledon title defence this year? A second-round defeat in Birmingham to world No 24 Barbora Strycova - the same player who handed out last year's thrashing at Eastbourne. We have learnt by now that using Muguruza's form as an indicator for grand slam success is futile. Despite her apparent struggles, no one should be surprised if she goes all the way again. Roger Federer is aiming to win a record-extending ninth men's singles title, and the top- seeded Swiss is rightly regarded as the favourite. Federer holds a huge advantage over his rivals after opting to skip the clay-court swing, meaning he should be the freshest physically and the most familiar with grass courts. However, in his two warm-up events, Federer showed signs of fallibility. Granted, he won the Stuttgart title, but he dropped the first set of his first match to world No 54 Mischa Zverev and was pushed to the limit by Australian Nick Kyrgios in the semi-final. Then in Halle, Federer faced match point in the second round against Frenchman Benoit Paire, and came through close contests against two unheralded opponents - world No 60 Matthew Ebden and world No 109 Denis Kudla - before losing the final to Borna Coric, who prior to the tournament had won only two grass-court matches his entire career. There is no doubt that Federer remains the man to beat at Wimbledon, but he does not enter the tournament as the all-conquering player of the past. Is he aiming to peak at the All England Club or are his powers, at the age of 36, starting to fade? Time will tell. A close eye has been kept on the fitness of former champions in the build-up to the men's singles event. Two-time champion Rafael Nadal suggested, after claiming a mind-boggling 11th French Open title, that he could miss Wimbledon. The Spanish world No 1 withdrew from the warm-up tournament at Queen's but has since made his way to the All England Club. Novak Djokovic was also unsure about his participation as he continues to rediscover his form and fitness after the elbow injury that saw him retire from his Wimbledon quarter-final last season. But the three-time champion from Serbia has taken his place at the start line. Then there's two-time champion and local favourite Andy Murray, whose fitness issues saw him make his return to competitive tennis only last month after nearly a year on the sidelines, and while he left it late to make a final decision, he too is competing. Despite their varying fitness concerns, all three players have joined Federer in the main draw at Wimbledon, meaning the so-called "Big Four" are all competing at a grand slam for the first time since last year's Wimbledon. Little is expected of Murray given his lack of match fitness, but Nadal - despite his minimal grass court preparation - should be regarded a contender, while Djokovic's run to the Queen's final suggests he can be a force at the All England Club. However, the "Big Four" are not the dominant band of players they once were and the likes of last year's beaten finalist Marin Cilic, world No 4 Juan Martin del Potro, and the talented yet unpredictable Kyrgios could view this tournament as a rare opportunity to strike.

Wimbledon talking points: Serena Williams' seeding saga and is Roger Federer fallible?

Ahead of the start of the grass-court grand slam, here are some key talking points