Today is Brock Lesnar's 34th birthday.

He may not be the heavyweight champion anymore, but he is still the UFC's biggest star. Lesnar came to the promotion in early 2008, just after the UFC's initial wave of reality show popularity had crested. When Brock made his UFC debut at UFC 81, Chuck Liddell vs. Tito Oritz 2 at UFC 66 was the biggest selling pay-per-view in the promotion's history with just over a million buys.

During Lesnar's reign of terror in the heavyweight division, he headlined four UFCs that broke the million buy barrier. That's 4/5 of the million buy events since he joined the promotion. UFC 114 featuring Rashad Evans vs Quinton "Rampage" Jackson which featured a very bitter grudge built over the course of the highest rated season of The Ultimate Fighter, is the only million seller without Lesnar since he joined the promotion.

Lesnar's peak came at UFC 100 when 1.6 million people bought the pay-per-view. Unfortunately, he was diagnosed with diverticulitis shortly thereafter and just hasn't been the same since. In the two years since UFC 100, Lesnar has only fought twice, going 1-1 against Shane Carwin and Cain Velasquez.

And not only did he split those fights, he looked bad in both of them, cringing and ducking when the punches start flying. He survived to submit Carwin thanks to Shane's shallow gas tank, but Cain Velasquez had no problem outlasting Lesnar's desperate charge at the start of their UFC 121 bout.

Then Cain made Brock look plain silly. If I hadn't seen it myself, I wouldn't believe that the fearsome Brock Lesnar, as intimidating a physical specimen as they come, would be stumbling across the ring in one of the most awkward and embarrassing displays I've seen in almost 20 years of obsessive MMA watching.

The bad luck just piled on after that. First Velasquez injured himself during the fight -- a 90% tear of his right rotator cuff, very serious. That took Cain out of the picture for most of 2011.

The UFC regrouped by booking Lesnar opposite Junior dos Santos, the #1 contender, to coach The Ultimate Fighter. Expectations were sky high. There was talk of Lesnar matching or even breaking the ratings Kimbo Slice brought to season 10.

Alas it was a flop. Lesnar kept a lid on his volatile personality. Dos Santos is probably the nicest, most humble man in MMA -- aka he's utterly dull. The ratings were awful and then things got even worse.

Lesnar's diverticulitis returned and this time he had surgery to cut out 12 inches of colon. Not fun. The UFC is hoping he'll return in early 2012, but let's face it, it won't be the same.

Lesnar's 34, nearing the end of his peak athletic years. The illness and surgery have had to have a huge impact on his training, physique and confidence. And speaking of confidence, the Carwin and Velasquez fights have destroyed Lesnar's image as an invincible viking, just imagine what damage they've wreaked inside his head.

BE reader nottheface broke down the numbers and made a strong case that Lesnar is solely responsible for the UFC's continued growth since 2008.

The UFC will survive without Lesnar and over time new stars will emerge, but there is nothing comparable on the horizon. The WWE built Lesnar as a popular attraction and there just aren't any WWE stars with comparable credible athletic backgrounds to duplicate the feat.

The UFC will have to build it's next breakout star on its own.

As a fan who enjoyed the Lesnar era immensely, I'll keep hope alive that he's got one last run for glory left in him. Here's hoping Mr. Lesnar has a good birthday and a speedy recovery. MMA needs him.