It could be that lightweight champion BJ Penn (15-5-1)'s utter dominance atop the division has set one past and one potential future opponent, Diego Sanchez (21-3) and Nate Diaz (11-5) respectively, on the run-- or it could just be that putting yourself on a starvation diet for weeks on end is, as it turns out, not conducive to maximizing one's athletic performance. In any case, both fighters have recently announced their intention to fight at welterweight in the immediate future.
In the case of Nate Diaz, the temptation is to frame the situation as a case of something simply needing to change. After starting his octagon career with five straight victories, the proud resident of Stockton, CA has won just one fight in his last four outings. Nate, who at twenty-four years old is likely still growing into his adult frame, at least partly attributes his recent failings to the difficulty of making weight and has decided, as a result, to fight at welterweight at least part-time in the future. At the same time, Diaz has also recently expressed a complete lack of interest in fighting BJ Penn, so it's tough to say if that played into his decision.
In recent days it has been rumoured that Diaz' debut at welterweight would be as early as March 27th at UFC 111: st-Pierre vs. Hardy. According to MMAWeekly.com, Rory Markham (16-5), who hasn't fought since being knocked out by current welterweight title challenger Dan Hardy at UFC 95, was set to be Nate's opponent.
However, it has since come to light that Diego "Nightmare" Sanchez, fresh of one of the most one-sided drubbings in UFC title fight history at UFC 107: Penn vs. Sanchez, also intends to fight next at welterweight. In Diego's case, this decision can be spun as more of a failed experiment scenario because welterweight is the division in which he fought most of his career and it is where some of his most iconic bouts have taken place. Sanchez was 2-1 at lightweight in his last three fights, but apparently felt his body is better suited to 170lbs after all. Since this news was released, Sanchez has found the time to as call-out the two welterweights he has lost to in the past:
YES IM GOING BACK TO WELTERWEIGHT IM LOVING MY NEW DIET.I WANT KOS OR FITCH BUT ANY TOP GUY WILL DO JUST WANT TO GIVE U FANS THE BEST FIGHT
...as well as politely proposing a match with Nate Diaz via his Twitter account:
I agree you go robbed... i hear your going up too 170 too i would love to welcome you to welterweight lets make it happen.