After the loss of UFC 181’s original headliner, UFC welterweight champion Johny Hendricks is suddenly off the bench and readying himself for his first title defense.

“It’s pretty exciting to get back,” said Hendricks (16-2 MMA, 11-2 UFC) on his rematch with Robbie Lawler (24-10 MMA, 9-4 UFC), which now headlines the Dec. 6 pay-per-view event at Las Vegas’ Mandalay Bay Events Center. “Vegas has always been a good place. It treated me very well when I lived there.”

The UFC booked Hendricks vs. Lawler 2 after middleweight champ Chris Weidman was forced to withdraw from the event with a broken hand.

It’s the second time the two have met this year after Hendricks outpointed Lawler to win the vacant welterweight title in March.

Although Hendricks was already one month into hard training when he heard Weidman was injured, he’ll kick it up a notch for the next 10 weeks in preparation for Lawler, who tested his will and forced him to fight through a torn bicep that necessitated a five-month layoff.

Hendricks and his camp originally estimated an early-2015 return with the UFC’s end-of-year pay-per-view schedule full, but the injury shuffle opened up a spot.

“The last time (I trained for Lawler) was a little weird circumstances, and I’m hoping I get through training camp a little bit smoother this time,” Hendricks told MMAjunkie Radio. “That’s really where my head’s at. I feel like I had a great game plan the first and second round, and I think I could have continued to do that the third, fourth and fifth.

“But we’re also adding on. There’s some other things we think we can do to Robbie.”

Hendricks won three of five rounds against Lawler in a “Fight of the Year” candidate and then underwent surgery to repair his arm. He said in his offtime, he spent time with his family.

The champ said he’s now floating around 208 pounds in the morning and is putting a plan together to come in lighter for his second bout with Lawler. At UFC 171, he struggled to make the 170-pound requirement for the title bout and needed a second attempt to make weight.

“And there’s other things we’re doing,” he said. “We’re doing bodypods; they tell you how much fat-free bodymass you have, so there’s a lot of things that are going to help me in further camps at 170.

“I just did all my bloodwork, and my pulse was 46 (beats per minute),” Hendricks added. “Then I jumped around and did their cardio test, and I got it up to 58, so the cardio’s getting there, and that’s how hard I’ve been working to get stuff going.”

Hendricks and Lawler could face enhanced drug testing for the event, which is overseen by the Nevada State Athletic Commission, a regulatory body that has increasingly used out-of-competition blood and urine testing at the expense of the UFC.

In his most recent fight in Las Vegas, Hendricks battled with now-former champ Georges St-Pierre over enhanced testing in advance of their title fight at UFC 167 this past November. St-Pierre won a controversial decision and then stepped away from the sport.

Hendricks said he supports enhanced testing if the UFC or the commission decides to use it.

“I know the UFC’s been doing a lot with WADA,” Hendricks said. “That’s really what’s going to change the sport, and it sort of has already. What’s really going to change it is the random (testing), like all of a sudden, somebody randomly calls me and I answer and they say, ‘This place, I’ll see you in an hour.’

“It doesn’t bother me because I don’t take anything. It’s easy for me to sit here and say certain things, but the stuff that they’ve already been doing, the UFC, the (NSAC), they’ve been doing a great job. We’re seeing a change.

“So realistically, the change that we’ve seen is making it harder to fight, which stinks, but you know that you’re cleaning up the sport. That right there shows that the UFC is willing to do what it can to keep it moving in the right direction, so I can’t complain at all.”

For more on UFC 181, stay tuned to the UFC Rumors section of the site.

MMAjunkie Radio broadcasts Monday-Friday at noon ET (9 a.m. PT) live from Mandalay Bay Resort & Casino’s Race & Sports Book. The show, available on SiriusXM channel 92, is hosted by “Gorgeous” George Garcia and producer Brian “Goze” Garcia. For more information or to download past episodes, go to www.mmajunkie.com/radio.