Gerard Whateley has opened up about why he swapped the ABC for a much smaller audience on Melbourne radio station SEN.

The veteran broadcaster, who announced his shock departure from Grandstand and Offsiders on Monday night, said after 13 years at ABC it was time to take a risk.

"I'm 43, I've been there [the ABC] since I was in my 20s," he told Fairfax Media. "It's my moment to go and have a crack at something else.

"I hope people will come with me and give me a chance," he said. "I'm not changing. They [SEN] want me for who I am. I love every sport that comes through Melbourne. We're a broad church and I want to be a conduit to that broad church."