Weidman (9-0) put himself squarely in the 185-pound title hunt on July 11 with a second-round knockout of Mark Munoz.
Weidman since has campaigned vigorously for a shot at titleholder Anderson Silva. But the champion isn't expected to fight again until next year, possibly against welterweight champ Georges St. Pierre.
White revealed earlier this week that if St. Pierre defeats interim 170-pound titleholder Carlos Condit in a bout expected to take place Nov. 17 at UFC 154 in Montreal, he likely will face Silva in 2013.
"I'm the man to take the title from Anderson Silva," Weidman said. "I'm the No. 1 contender in the division. But with Anderson not fighting for the rest of 2012, I want to stay busy, keep getting better and take on the best out there.
"I'm the best middleweight in the world and I'm going to prove it against another top contender."
Boetsch, a former light heavyweight, has not lost a fight since dropping to 185 pounds. He is 4-0 at middleweight and 16-4 as a mixed martial artist.
"This is a big fight for the middleweight division," Boetsch said. "I'm better than ever and ready to prove that I am next in line for a title shot."
Boetsch cemented a spot in the upper echelon of the middleweight division July 21 with a split decision over former Bellator 185-pound champion Hector Lombard, who entered the bout on a 25-fight win streak.