Weidman, who confirmed the injury Wednesday, was scheduled to face Boetsch at UFC 155 in Las Vegas. Boetsch will now fight Constantinos Philippou on the card.
Newsday.com reported Weidman's injury earlier.
"I hit a double-leg and landed weird and hard on my shoulder, and it popped," Weidman told ESPN.com. "I had an MRI on it. I tore my labrum, and I could have a separation. There could be some other things, but we haven't heard back from the doctor. The radiologist told us all that much so far.
"It looks like I'm going to need surgery. It's my right shoulder."
The injury could not have come at a worse time for Weidman. Three weeks ago his home on Long Island was damaged by Hurricane Sandy. He's been on an emotional roller coaster the past few weeks, he said.
"I go up and down from being depressed about it to being optimistic," Weidman said, "with Hurricane Sandy happening, then this. The good thing is I get to focus on my family throughout the holidays. The bad thing is that I'm going to have to have surgery and miss on the fight of my life.
"The one thing I did not want to happen, and was scaring me this whole camp, was for me to get hurt. I need the money with everything that went on with Hurricane Sandy. That (money) was going to be used when I got that fight right at the end of the year."
Weidman, who is ranked second by ESPN.com among 185-pound fighters, has a professional record of 9-0. His name is constantly mentioned as the man likely to get a title shot against middleweight champion Anderson Silva. Silva, however, is expected to face welterweight champion Georges St-Pierre in a non-title superfight that is being targeted for May.
Weidman cemented himself as the consensus top middleweight contender on June 11 with a second-round knockout of Mark Munoz. The only other middleweight contender being mentioned for a title shot is Michael Bisping.
Despite this recent setback, Weidman remains confident that he will become champion someday.
"I'm going to make the best of it, and hopefully it will be a blessing in disguise," Weidman said. "One way or another, I'm going to get that belt."