AFL premiership player Tom Boyd has spoken at length for the first time about his mental health struggles and reasons for quitting the game, saying he had not enjoyed playing footy "for a long time" before calling it quits in May this year.

Key points: Tom Boyd said he had suffered insomnia and depression while playing professional AFL

Tom Boyd said he had suffered insomnia and depression while playing professional AFL But he told Fox Sports his mental health was not the reason he left the game

But he told Fox Sports his mental health was not the reason he left the game He said he had contemplated retiring since first being drafted as a teenager

Boyd was just 23 when he left a high-profile contract with the Western Bulldogs after helping secure their 2016 premiership flag two-and-a-half years earlier.

Boyd took time off for his mental health in 2017 and told Fox Sports on Tuesday night he was battling severe insomnia at the time, on top of his public diagnosis with clinical depression.

But he said his mental health struggles, which began affecting his physical health as well, were not the reason he walked away from the sport professionally.

"Call it a crisis of vocation or something," he told the Open Mike program.

"I just didn't enjoy playing footy and I didn't enjoy it for a long time. And doing something that is ultimately an extremely challenging job, that you also don't enjoy, is very hard to maintain over a long period of time."

Boyd was picked first in the 2013 draft by the GWS Giants, but he left Sydney the following year as part of a mammoth trade deal with the Bulldogs, which saw the Bulldogs' then-captain Ryan Griffen head to Western Sydney in place of Boyd and a future draft pick.

He said he initially thought he was experiencing "lingering homesickness" while living away from Melbourne and did not realise he was experiencing something more serious.

"I think for so long I was incapable of dealing actually with the emotions I was facing," he said.

"Whether it be pressure from the media or pressure from my own performance … I sort of just put a brave face on and said, 'don't worry about it, I'm fine'. I think that's where my problems really started."

Player had contemplated retirement for years

Boyd was a key player when in 2016 the Bulldogs ended a 62-year premiership drought with a 22-point victory over the Sydney Swans.

"The euphoria of that whole experience covers up pretty much anything … nothing could have stopped that sense of joy," he said.

But he said it only temporarily masked the broader issues he was having with the game, which got worse in coming years.

Boyd was a key member of the Bulldogs' premiership team. ( AAP Image: Julian Smith )

In the 30-minute sit-down interview with Mike Sheahan, Boyd revealed he was "positive" he was doing the right thing when he left the club, effective immediately, in May.

"Because I first thought about retiring in 2013, 2014 when I was with the Giants."

He said it was fair to say he loved football but did not love the AFL.

"I think I had a really pragmatic relationship with footy … I think I was very good at it, particularly when I was young. And I think that most people get pushed into the profession that they're good at, whether they choose it or not.

"I think footy probably chose me, more than I chose it."

Boyd's transfer to the Bulldogs came with a hefty price tag — a million-dollar-a-year contract that he gave up when he quit.

"I think the more money I've gotten, and particularly because of the way my contract was shaped, I think the thing that I realised was that it didn't matter how much money I got, it wasn't making me any happier," he said.

Boyd is now studying business at university and although he has played for the Norwood Football Club in the local league, said he was sure he would never want to return to the game.