The Sydney Swans won a three-way bidding war with St Kilda and Essendon to secure the services of Irish teen sensation Colin O'Riordan.

The 19-year-old was paraded before the media at the NAB AFL Draft Combine on Sunday, and AFL International Academy Manager Tadhg Kennelly said the County Tipperary product had a tough decision to make on his future.

Kennelly insists he didn't cajole his compatriot into picking his former club and says the star Gaelic footballer's decision came down to "preference".

"He spent a day at the Swans, Saints and Bombers and they were jumping all over him as soon as they saw him," Kennelly said.

"He decided at the end of the day Sydney was the best fit for him and I'm delighted, being a former Swan."

"It's no surprise really the way he conducts himself and his character, he's a real Sydney footballer."

While he's ecstatic to receive an AFL contract, O'Riordan says it might take time to get used to wearing the Swans colours.

"I grew at home hating the red and white because it's (rival county) Cork," he joked.

"The second I stepped foot in Sydney I absolutely loved the place, the people there and the atmosphere, it was just something else.

"It's going to hard and I have a lot of work to do because I'm a good bit behind the Australian boys."

Swans recruiting manager Kinnear Beatson said the club had no hesitation in offering the Irishman a two-year international rookie contract.

He envisaged O'Riordan playing a similar role to the one Kennelly performed with aplomb.

"We think he'll play as a small-medium defender running off half-back," Beatson said.

"The thing that really impressed us is how well he kicks the footy for a guy that's grown up with a round ball, but also his hands were very good over his head and at ground level, and he's just so competitive."