If someone had said before the French Open that Stan Wawrinka would be standing in Court Philippe Chatrier last Sunday holding the Grand Slam trophy they would have been laughed at. The draw looked set for a classic Federer v Djokovic/Nadal/Murray final, and so it continued to seem that way until the quarter finals.
Suddenly Federer suffered a heavy defeat to his Swiss compatriot and Nadal showed he was nowhere near the standard needed to retain his French Open title. The cracks in tennis' biggest names were starting to show.
Federer shrugged the defeat off, claiming he was already focusing on the grass court season and would bounce back from the defeat without much grief, similarly Nadal was looking towards the upcoming grass court swing.
Many would argue with Djokovic, Federer and Murray occupying the top three places in the world rankings that the Big Four still have a firm grip on the ATP tour. However, of the the four current Grand Slam champions, two of them are players outside of this elite group. Both Marin Cilic and Stan Wawrinka hold a Grand Slam title to their name, with the latter winning his second title in as a many years.
It seems that with Federer and Nadal off their game, neither Djokovic or Murray can afford to be even slightly off their game in order to prevent another outsider from snatching a major trophy from their grasp.
Players like Tomas Berdych and Jo-Wilfried Tsonga will also be watching carefully for a chance of a surprise upset in the near future in a major tournament as the big trophies become seemingly achievable for players that it seemed were destined to never win one.
Nadal in particular is a cause for concern, the clay court season tends to be where he builds up his most ranking points as lately the grass and hard court seasons have caused troubles for his ailing knees. He now sits in 10th position in the ATP rankings, his lowest since 2005, and will face tougher draws as a result in his quest to make the ATP World Tour Finals in London.
Struggles to reach this prestigious tournament are something the "Big Four" have become accustomed to. Andy Murray only qualified for 2014 edition in the final tournaments of the season while Federer needed a late push the year before to secure his place in London.
It seems that in their attempts to keep a stranglehold over the chasing pack, these top players are beginning to blink. While Djokovic surrendered his best chance at a career slam last Sunday it seems he is the only one of these players who have been able to remain a consistent force at the top of the tennis world rankings. Should his level drop we could see a new era of tennis history unfold before our eyes in the not too distant future.