REPORT: Rihanna Canceled Oscar Performance

Did Rihanna's injuries cost her a once-in-a-lifetime opportunity to perform at the Oscars?

A New York Post report claims that the singer was supposed to be a surprise guest on last night's show -- but that she had to cancel because she's still recovering after allegedly being beaten up by boyfriend Chris Brown.

If their info is correct, the Umbrella star could have been up there with the likes of Beyoncé, John Legend, Zac Efron, Vanessa Hudgens, Anne Hathaway and Hugh Jackman.

The star, who suffered horrific cuts and bruises in the alleged attack on Feb. 8, has already had to pull out of a performance at the Grammys.

She's now said to be lying low in L.A. while she deals with the aftermath of the incident.