David Koch or 'Kochie' has revealed on radio that he wasn't invited to his co-worker Sam Armytage's farewell lunch.

Armytage hosted an intimate lunch at a restaurant in Sydney's Rose Bay after her last morning on Sunrise, but Koch didn't make the cut.

Armytage was joined by her husband Richard Lavendar, several close friends, Sunrise executive producer Michael Pell and Morning Show host Kylie Gilles.

Koch and his new host Natalie Barr was asked on the Kyle and Jackie O show why the pair weren't invited to the lunch by host Kyle Sandilands.

“Well, we didn’t know about it,” Kochie told the radio duo.

Barr and Kochie had "known for a couple of months" that Armytage was thinking of leaving the hit breakfast show, but Barr was still surprised when the job was offered to her.

“There was a call from the big boss who said, ‘How about it?’ I said, ‘Oh, OK, yeah right,’” Barr said on KIIS FM. “I was actually really nervous. I was so nervous that one of the bosses who called actually said, ‘Are you sure you want this?’”

Luckily, she accepted the job after a pep talk from her husband.