Veteran pop star Bobby Vinton has had to turn down the opportunity to perform at pal Joan Rivers' funeral on Sunday (07Sep14) after struggling with a bout of pneumonia.

The late comedienne had detailed her ideal send-off in her 2012 book, I Hate Everyone... Starting with Me, revealing she wanted it to be "a huge showbiz affair with lights, camera, action..."

She went on to add, "I want it to be Hollywood all the way. I don't want some rabbi rambling on; I want Meryl Streep crying, in five different accents. I don't want a eulogy; I want Bobby Vinton to pick up my head and sing Mr. Lonely."

Rivers' family is planning to celebrate her life at a service at New York's Temple Emanu-El, the synagogue where she was a member, this weekend, but Blue Velvet hitmaker Vinton won't be able to attend due to ill health.

The 79-year-old singer's representative tells Tmz.com he is currently recovering from the lung infection and therefore won't be able to perform the 1964 hit, although he is considering recording a video message to be played during the ceremony.

Rivers died on Thursday (04Sep14), aged 81, after failing to recover from a cardiac and respiratory arrest suffered on 28 August (14), during a routine throat operation at a Big Apple clinic.

An initial autopsy on her body was completed on Friday (05Sep14), but coroners could not find a clear "cause and manner of death". Toxicology testing is currently underway.