Just last week, Brock Lesnar was being touted by many as having the potential to become the greatest heavyweight fighter in UFC history. Even with only six fights under his belt, Lesnar had made significant strides in the short time since his first UFC fight in June 2007.

A fighter who began with questionable technique relying solely on his incredible size and brute strength developed into a fighter who has a skill set to complement his enormous physical stature. Lesnar showed noticeable improved from fight to fight and was a far different fighter than the man who lost by submission to Frank Mir at UFC 81 in February 2008.

After reeling off four consecutive wins against formidable opponents including Randy Couture, Frank Mir and Shane Carwin, Lesnar was at the top of his game. After his submission of Carwin to unify the Heavyweight titles at UFC 116, Lesnar showed that he could beat an opponent in multiple ways.

Unfortunately for Brock Lesnar, his ascent to the greatest heavyweight fighter in UFC history took a major detour last week against Cain Velasquez at UFC 121. Not only did Lesnar lose the fight, he was completely pummeled by Velasquez resulting in a loss by TKO at the 4:12 minute mark in Round 1.

Lesnar now faces the unenviable task of coming back from the worst loss of his short career.

It's not like Lesnar is unfamiliar with adversity. It was only a short time ago when he had to pull out of a scheduled fight against Shane Carwin at UFC 106 due to an undisclosed illness. Later is was revealed that he was suffering from both mononucleosis and diverticulitis, two conditions that not only put his career in jeopardy but also his life.

When Lesnar returned in the summer of 2010, he proved to be in the best shape of his life. With his well documented competitive drive, don't count on Lesnar being down for too long.

Perhaps the most interesting path back to dominance would be by way of a rubber match with Frank Mir. It's no secret that there is quite a bit of bad blood between Lesnar and Mir, and a third match would be a great draw and provide a stepping stone for Brock's trip back to the top.

Another possible option could be a rematch with Shane Carwin. Carwin is set to fight Roy Nelson at UFC 125, and if Carwin were to win that fight, Lesnar could garner significant attention if he were to achieve another victory.

Regardless of exactly which opponents lay in the future for Brock Lesnar, never underestimate his ability and competitive spirit. If he continues to improve the way he has throughout his short time in MMA, a rematch with Cain Velasquez could come sooner rather than later.

And it wouldn't be wise to bet against Lesnar in a rematch.