Fans were disappointed when Rihanna backed out on her Grammy Awards’ performance.

RiRi was set to perform her new hit, “Kiss Me Better,” off of her latest “Anti” album at the Grammys, but she bailed hours before the show. She was supposed to appear alongside “Late Late Show” host James Cordon.

The singer has been diagnosed with a serious case of bronchitis prior to the event and doctors reportedly advised her to pull out. Rihanna’s rep told the Daily News that her doctor told her to rest her voice for 48 hours because she was at risk of hemorrhaging her vocal chords.

“The antibiotics she has been on for three days did not kill the infection adequately therefore she cannot perform safely,” RiRi’s rep added.

However, there has been a rumour that belies the story.

TMZ cited sources claiming the “Rude Boy” singer went on a “hysterical” outburst after experiencing displeasure with her pre-show rehearsal.  It is unclear what triggered Rihanna’s meltdown, but TMZ noted that the Barbados singer was very upset and screaming loudly.

The sources added Rihanna sounded fine during the rehearsals. Daily News pointed out that the singer also sounded in top form when she performed at Lionel Richie’s charity event two days before the awards night.

RiRi did not also appear on the red carpet at the Grammys. TMZ reported the “Work” singer went home after the rehearsal because she was very upset to stay and watch the show.

Rihanna apologised for missing the event on Monday and posted on Twitter: “#NAVY so sorry I couldn’t be there ….. Thanks Grammys and CBS for your support tonight.”

This is not the first time Rihanna has canceled her Grammys performance. She also bailed out in 2009 after her then boyfriend singer Chris Brown was charged with assaulting her, Daily News wrote. Brown pleaded guilty to felony assault later that year.