Bethanie Mattek-Sands thanks her fans for their support as she reveals that she dislocated her right patella and ruptured her patella tendon and will require surgery. (2:48)

During a 15-minute Facebook Live chat Saturday morning, American Bethanie Mattek-Sands said she dislocated her kneecap and ruptured her patella tendon in her right knee when she slipped and fell during her second-round match at Wimbledon on Thursday.

"I'm heading to New York City tomorrow to see some more doctors to see what's really going on with my knee," she said. "I'm going to be needing surgery. I'll be out for a while."

Wearing a "Bananas Yo" T-shirt from her trainer Shaun T's line, colorful shorts and a black brace on her right leg, Mattek-Sands addressed her fans directly and at times fought back tears as she described Thursday's events.

"I remember taking a step, my leg not being able to hold me, and I went down," she said. "My knee felt tight. I took a look at it, and something was wrong. I knew it was dislocated or broken. At that point, I freaked out. That's probably when you all heard me drop an f-bomb. It was one of the most painful injuries in my career.

"I was giving some of the medics a hard time because I didn't feel like any of the pain medication was kicking in. I just remember everyone getting ready to straighten my leg, and I told [my husband] Justin, 'If anyone straightens my leg, I'm going to kill you.' I think you heard that, too. I was in pain. I said, 'I want to be knocked out in the hospital before they do it.'"

After being transported to nearby Parkside Hospital, Mattek-Sands said the pain medication began to take hold, and she has no memory of doctors repositioning her knee.

"When I woke up, I remember all these thoughts going through my mind about rehab and my chance at Wimbledon, doubles with Lucie [Safarova]," she said. "Anyone that knows me knows I'm pretty positive and I smile a lot ... and I was having a hard time. I want to let everyone know that there are times that even I'm upset and down, but I want to stay strong and get through these times. ... I've read most of your messages. I can't reply to all of them, but the support has been amazing. I'll get through this."