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FILE - In this May 5, 2013 file photo, Justin Timberlake performs at the MasterCard Priceless Premieres concert in New York. The first of Timberlake's two concerts at Madison Square Garden has been postponed. The singer posted on his Twitter feed Wednesday, Feb. 19, 2014, that the postponement is due to health reasons. (Photo by Charles Sykes/Invision/AP, File)
NEW YORK—The first of Justin Timberlake's two concerts at Madison Square Garden has been postponed.

The singer posted on his Twitter feed Wednesday that the postponement is due to health reasons. The show originally scheduled for Wednesday has been rescheduled for Friday.

Timberlake apologized on Twitter and said, "It kills me to have to do this. I hope to see you all on Friday."

On its website, MSG says ticketholders can get a refund if they want, starting Thursday morning.

The Thursday night performance in Timberlake's "The 20/20 Experience World Tour" is expected to take place as planned.