Music superstar Lady Gaga, currently on a “Mayhem Ball” world tour set to soon come to the United Center in Chicago, unexpectedly canceled a show Wednesday, minutes before she was to take the stage.

The singer, who was performing the final of three shows at the Kaseya Center in Miami, announced the news on Instagram, saying she suffered a “vocal strain” during warmup and rehearsal.

“Hi everyone,” the Instagram story began. “I am really so so sorry but I need to postpone tonight’s show in Miami. During rehearsal last night and my vocal warmup tonight my voice was extremely strained and both my (doctor) and vocal coach have advised me not to go on because of the risk it poses.”

Lady Gaga’s full message to showgoers can be found below:

“I want to be hardcore and just push through this for you but I don’t want to risk long term or permanent damage on my vocal cords,” she continued. “There is a significant risk based on all our combined experience with a show like ours and as you know I sing live every night –and even though this was a hard and agonizing decision I would be more afraid of the long term implications on my voice. I hope you can forgive me and accept my sincerest apologies for any disappointment. Let down, inconvenience I am so so sorry I tried so hard to avoid this. I take serious care of myself to be able to put on this highly demanding show. I love my fans so much, respect you and hope you can accept my sincere regretful apology. We are trying to reschedule the show as quickly as possible.”

Shortly after the announcement, the Miami venue posted that Wednesday night’s performance of the “Mayhem Ball” was postponed.

“During her warmup tonight Lady Gaga experienced significant vocal strain and has been advised by her ENT and vocal coach to not perform. Information on the rescheduled date and the process for refunds will be issued soon.”

As of Thursday, Lady Gaga’s next scheduled shows were set for Saturday and Sunday at Madison Square Garden in New York, followed by three shows next Wednesday, Thursday and Saturday at Scotiabank Arena in Toronto.

According to her website and the venue’s calendar, Lady Gaga’s Chicago United Center shows are listed for Sept. 15, 16 and 17, with tickets still available.

The United Center and Live Nation did not immediately respond to NBC Chicago’s request for comment.