Rihanna is battling a combination of laryngitis and bronchitis, which is threatening her performance with Eminem at the Grammy's on Sunday night, RadarOnline.com is exclusively reporting.

One day after pulling out of a benefit concert citing illness, she was spotted at rehearsals on Friday for the 53rd annual awards and is apparently still on for the big show.

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"Rihanna will perform with Eminem, as scheduled,” a pal of the Umbrella singer told RadarOnline.com.

She Tweeted on Friday that she would be rehearsing, despite suffering from bronchitis.