Garry Lyon has paid an emotional tribute to former AFL star Danny Frawley as he spoke of the "utterly, impossibly heartbreaking" reality of his friend and former colleague's death.

Key points: Lyon returned to his radio show for the first time since Frawley's death

Lyon returned to his radio show for the first time since Frawley's death He opened the program by remembering his friend's "relentless" pursuit of laughter and mischief

He opened the program by remembering his friend's "relentless" pursuit of laughter and mischief He said it seemed "life will not be as much fun again" without Frawley in it

Frawley, a former St Kilda captain, Richmond coach and media personality, died in a single-car crash in western Victoria on Monday.

The former potato farmer affectionately known as 'Spud' had his 56th birthday just the day before.

Lyon, a former captain of the Melbourne Demons and long-time colleague of Frawley, said he "knew him as an opponent first, but not long after as a work colleague at the AFL and then even more quickly as a friend".

Lyon spoke of his shock and sadness during his return to the breakfast radio show he hosts on sport network SEN.

"It's been a difficult three or four days. In fact, it's been a horrific three or four days, and the best way I can deal with these things is, I write stuff down," Lyon said.

In an eight-minute tribute where he at times choked back tears, Lyon said Frawley "walked through life with a perpetual smile and a nose for mischief".

Danny Frawley's death shocked the world of football. ( AAP: Joe Castro )

"He had fun written all over him, laughter was the fuel that drove him and he was relentless in his pursuit of it," he said.

"As I sit here today and try and make sense of the tragic circumstances of the 9th of September that saw him taken away from us so swiftly and brutally, I'm trying desperately to define my relationship with him so that the sense of grief and loss can have some perspective to understand why it hurts so much.

"And I arrived at the conclusion that it's because he was just so relatable to me."

Lyon reminisced about the pair's early days working at the AFL — where 'Spud' would play games and pranks during serious press conferences — and their role in the commentary box for Triple M decades later.

Frawley had been open with his mental health struggles in recent years and had begun to use his media platform to encourage others to seek help.

"I'll never forget his empathy nor his compassion and I know I'm not the only one to benefit from his love and counsel," Lyon said.

Lyon said it was "utterly, impossibly heartbreaking" to know Frawley would not be around any more.

"Today it just seems that life will not be as much fun again without Spud Frawley in it."

Sudden death 'hard to get your head around': Jason Dunstall

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 51 seconds 51 s Jason Dunstall reflects on the death of his close friend and "great mate" Danny Frawley.

On Thursday night, Lyon and Jason Dunstall — Frawley's long-time on-air partner on the Bounce TV program — were interviewed on Fox Footy's AFL 360 about their friend.

Dunstall expressed a sense of helplessness in trying to understand the tragedy.

"It's hard to get your head around," he said.

"It's [depression] an illness I'll never ever understand. I hate its guts but I can't get a handle on it. It just seems so senseless and you're just left with this giant void.

"It doesn't matter how devastated we are, there are family members who are 1,000 times worse off and I can't comprehend that," he added, saying he had communicated with Frawley's family by text because he knew he would not be able to talk on the phone.

The former Hawthorn great said he had learned of Frawley's death via a phone call from journalist and presenter Mark Robinson.

"I basically had no feeling for hours, and it wasn't until I saw a replay of [AFL] 360 doing a tribute and that's when I lost it and burst into tears and couldn't stop crying but I hadn't cried until then because I wasn't accepting what had happened."

An emotional Dunstall said he would not be able to re-watch the final show he had done with Frawley last weekend and admitted he was struggling to recall some of the funny things the pair had done together in their 13 years on-air and elsewhere.

"You sit there trying to remember all the little things that we did and that we said — God I wish I could remember some of the more specific things, because I have never laughed so much in my life as the times I've spent with him."

"It's funny, he had some time off I don't know how many years ago now, and that blindsided me, because I worked with the guy every week and we had so much fun together and I wasn't aware of anything, I didn't see any of the signs," Dunstall said.

"I'd make a point of asking him every now and then 'how're you going' until you get to the stage of feeling like you're bugging him so you stop asking. Then you think, should I have been more attentive, should I have seen something, should I have noticed something, should I have said more — what can you do?

Asked how he would remember Frawley, Dunstall said: "It's hard to answer. He's just a great mate, it's impossible not to love him."