SAM DAY is slowly starting to deliver on his limitless promise, and the young Gold Coast forward puts it down to a renewed dose of confidence.

Standing 196cm and filling out to 103kg, Day is near enough to the perfect athlete for modern day football.

After forgoing promising junior careers in both baseball and basketball, Day was taken with the third pick in the 2010 NAB AFL Draft, with the Suns hoping he would be their long-term full forward.

He is big, broad and agile, but struggled to make an impact in his first three seasons.

It's generally accepted that key position players take longer to develop, and Day was not helped by a string of injuries in those early years.

He plays his 50th career game against St Kilda on Sunday, on the back of two defining moments in 2014 that show the quietly-spoken 21-year-old has turned the corner.

In the round three QClash against the Brisbane Lions, Day took three second-quarter marks on the lead and converted each one from 45m to keep his team's head above water, in a game they would go on to win comfortably.

His acceleration to get away from Daniel Merrett and Justin Clarke, then copybook goalkicking on each occasion encapsulated just why the Suns were so keen on him.

Then two weeks ago, Day did the unthinkable and ran down North Melbourne's Brent Harvey after giving him a 5m start.

"Confidence has always been a problem and I've been working on that with the coaches," Day said.

"I just feel like I've got the ability, and now I just need to have a go at things to show I can do stuff which I've always believed I can do but have almost been too shy to show."

Day kicked 24 goals in his first 42 games, and his 11 in the first seven games this season, alongside fellow talls Tom Lynch and Charlie Dixon, have been a major reason behind Gold Coast's 5-2 start.

"I think I've been able to show I’m athlete that I was projected to be when they drafted me," he said.

"I feel like I can now start repaying them for their faith and the actual times they've given me games that I probably wouldn't have got at other clubs."

Twitter: @AFL_mikewhiting