Former world's no.1 Rafael Nadal bowed out from the China Open on Thursday, losing to unheralded Martin Kližan in three sets. Recently returning from a right wrist injury, his defeat to the Serbian prompted many fans and analysts to worry about the current status of the 14-time Grand Slam winner moving forward.

Is he okay? That is perhaps the pressing question the Majorcan bull is facing right now after an unexpected setback against the world's no.58 Klizan, who's boasting only two career singles title around his belt.   

Coming off a wrist injury that sidelined him for the entire North American season, the 28-year old Nadal was greeted with pessimistic opinions concerning his competitive form for the remainder of the 2014 tennis season.

However, Nadal silenced his critics two weeks ago after dominating Jo-Wilfried Tsonga in an exhibition game in Astana, Kazakhstan. It marked the first match Nadal played against a fellow ATP player after announcing his decision not to defend his titles at the Rogers Cup, Cincinnati Masters and US Open championships.

Through the first two rounds of the China Open, the Spaniard was in cruise control as he easily dispatched top-10 netter Richard Gasquet and Peter Gojowczyk. Then disaster struck again in the third round against Klizan.

Nadal, who has winning records against Novak Djokovic, Andy Murray and Roger Federer, has been losing matches against unseeded opponents more than any of his fellow Big Four rivals had as of late.

While a wrist injury is far from a career-ending one, there's a big question if Nadal will ever become a dominant force in men's singles play, especially with the speedy rise of Kei Nishikori, Stan Wawrinka and Marin Cilic.

The landscape has certainly changed over the past 10 to 12 months. The mantle of invincibility of the fabled Big Four is no longer evident, as young guns begin to make their move in this new era of tennis.

As talented as Nadal is, he will surely be in the mix for major titles / Grand Slam championships in the future. However, unlike his status when he piled up 10 singles title last year, he will no longer stuck fear into the hearts of his opponents who might have been emboldened by epic wins by youngsters like Nick Kyrgios and Klizan.

Perhaps, a new age in men's tennis has arrived, an era where Nadal, Djokovic, Federer and Murray are nothing more but mere combatants in now a wide-open Battle Royale.