On Monday, Perth radio DJ Brad Fitzgerald told listeners he thought Fremantle captain Nat Fyfe was heading out the door and going to St Kilda come season's end.

On the 'Carmen & Fitzi' show on 96FM in Perth, Fitzgeald said Fyfe had all but accepted a multi-million dollar deal to join the Saints in 2018.

“The offer is worth $1.5 million a season and it is - as far as legally wise - it’s virtually accepted,” Fitzgerald said on Monday morning.

“He can’t sign yet but it’s basically a done deal and he is going to St Kilda.”

Despite both Fyfe's management and St Kilda coach Alan Richardson denying the story just hours after it was released, Fitzgerald spoke on the radio again on Tuesday and stood by his comments.

“I have a credible and trustworthy source who gave me the information,” he said.

“With contract negotiations, I suspect there are a lot of agendas at play here."

Fitzgerald also took a shot at people who were questioning his validity by asking "why should we believe someone from breakfast radio?".

“If it’s so unbelievable why are you talking about it?," he said.

“I either have nothing of worth to listen to and you ignore me, or there is actually something about this.”