Nick Diaz’s un-retirement is only one day old, and already the onetime welterweight title challenger and Stockton native son is casting a wide net on future opportunities.

Diaz anticipates no issues fighting ex-champ Anderson Silva next year at middleweight, noting his walk-around weight can go as high as 200 pounds. But he claims he can compete afterward in three different classes.

“I think that’s one of my strengths,” Diaz (26-9 MMA, 7-6 UFC) said today during a conference call in support of his meeting with Silva (33-6 MMA, 16-2 UFC), which headlines UFC 183 on Jan. 31 in Las Vegas. “I could probably fight, at a time, I thought, at any weight. I’m no bigger than I used to be now.

“I’m getting a little older, but I always thought I could fight at a catchweight at 160, or fight at 170, 185, maybe even at 155. My brother (Nate Diaz) seems to be able to do it. But I also think I could fight at 185 pounds, as well. I would love to prove (wrong) any disbeliever.”

For now, Diaz will go to work on proving wrong the doubters who believe he’s in over his head against Silva. In early betting lines, he is a 3-to-1 underdog.

With the bout six months away, the 30-year-old fighter said he’ll get himself back into fighting shape in his native Stockton, Calif., while also traveling to San Francisco to work with UFC lightweight contender Gilbert Melendez, as well as in nearby Sacramento. He currently resides in Dallas, where he said he’s getting new tips on preparation.

Silva, a career middleweight, can walk around in the range of 220 pounds when he’s not fighting and previously has competed at light heavyweight. But Diaz said he won’t be at a disadvantage when they lock up in the cage.

“I’m pretty heavy, and I naturally don’t really have a hard time gaining weight,” he said. “I put on a lot of miles and a lot of work just to get down under 185 pounds or under 178 pounds or so for the (weight) cut.

“It can be pretty rough making 170 pounds, especially if I have fights back-to-back, because it’s just real easy for me to put on weight. That can happen real quick when you only have a small window to try to live life in between a fight.”

Diaz has had 16 months as a civilian following his unsuccessful bid for the welterweight title in March 2013 against then-champ Georges St-Pierre, which marked his second straight loss after a decision setback one year prior against Carlos Condit in a fight for the interim welterweight belt.

The former Strikeforce champ subsequently retired from the sport, but later flirted with a comeback with the caveat that the financial incentives had to be right. Meanwhile, he remained contractually bound to the UFC and turned down several fight offers from the UFC. On Tuesday, after several months of relative silence, the UFC announced it had signed the fighter to a new three-fight deal.

Diaz twice said he “can’t complain” about the money he is receiving for his return and said his relationship with UFC executives is good.

In January, fans will see which fighter is better suited to a comeback. Silva, 39, will not have fought in 13 months when he steps into the cage against Diaz after suffering a broken leg in a failed bid to regain the middleweight title from Chris Weidman.

For more on UFC 183, check out the UFC Rumors section of the site.