Rihanna Envies Kendrick Lamar: 'Underwhelming' Grammy Awards Hype, Performance Breakdown?

Rumors now suggest that Rihanna suddenly cancelled her highly-anticipated Grammy Awards appearance primarily because of Kendrick Lamar.

The To Pimp A Butterfly rapper's phenomenal performance continues going viral online:

But during rehearsals, RiRi apparently felt a bit too overshadowed by Lamar's powerful onstage production. An alleged insider tells the infamous gossip webloid Page Six:

"She felt like her performance couldn't compare [to some of the other artists'], and she was trying to avoid the embarrassment because she knew it wasn't the right comeback performance. She said, 'I'm not doing this.'"

And later during the live show, it was officially announced that she couldn't perform due to bronchitis.

Another snitch insists that her "Kiss It Better" practice session simply wasn't good enough:

"It was underwhelming... The performance was like a throwback to an '80s talk show. James Corden was going to introduce her, and she was supposed to walk over, talk to him, then gyrate on the mic. People were watching like, 'Oh, is that it?' She was singing parts of the song live, but it had a lot of recorded vocals [in rehearsal]. We were surprised when she rehearsed the ballad [all the way through], because we thought she was going to kill it and come back with [her more upbeat single] 'Work.' It didn't seem like Rihanna" (via Bossip.com).

The same source concludes that producers weren't too pleased:

"It was an intense conversation. It didn't seem like they were discussing a doctor's note. [She] looked upset after rehearsals and a doctor came to see her... After the doctor talked to her and told her the diagnosis, she was forced to pull out."

So, what's up with the beloved Barbadian BadGal - perhaps she's just in an Anti slump?

Rihanna Depressed? No Music Inspiration & Boyfriend Stress Leads To Health Scare

Maybe things will get better after tonight's scheduled "Work" performance with Drake at London's popular Brit Awards (Wednesday, February 24). Sound-off in the comments section below, MstarsNews readers!