PORT Adelaide great Kane Cornes believes Nick Blakey is close to being one of the absolute elite players in the AFL, saying "the sky's the limit" for the dashing Sydney defender.

Blakey was one of Sydney's best in their first-up win over Melbourne on Thursday night, setting up several attacking plays with his run off half-back and penetrating kick.

He also defended strongly when matched-up against a variety of Demon players, getting the better of both tall (Josh Schache, who is 199cm) and small forwards (Charlie Spargo, 173cm) as the Swans restricted their opponents to just nine goals on the night.

Cornes says Blakey, 24, is developing into one of the best players in the competition.

"I'm trying to work where he actually sits in the elite category of player in the game," Cornes told The Round So Far.

"He breaks the lines with speed and he's a beautiful kick, but then he can ... play on the opposition's best key forward. He did that last year as well when Sydney had all those injuries; I remember in Gather Round (against Richmond) he was enormous playing above his height. He plays whatever role he's asked.

"He's closing in on being a top-15 player in the League for me, Nick Blakey. I'm a huge fan of him. Every time I see him I think, 'wow, I'd love to have him in my team'.

"He's one of the most watchable players in the game and the sky's the limit on how good this guy can be."

Cornes highlighted two passages of play from Thursday night that underline Blakey's versatility in defence and threat in attack. Having first won a free kick in a marking contest with Dees tall Jacob van Rooyen late in the second quarter, Blakey then took a contested mark against Spargo at the start of the third before launching an attacking play with a piercing kick through the centre of the ground.

Having started his career as a forward, Blakey said last year his move into the back half forced him to work on his defensive game, which he had previously not prioritised.

"I didn't have a defensive bone in my body and that was probably the downfall of me as a player, early days," he told AFL.com.au ahead of his 100th game last August. "But transitioning down back, you've got nowhere to hide out there.

"A lot of what gets said is about my run and dash, but what I really pride myself on and what the coaches really want me to do is defend well, and usually the other stuff comes off the back of that."

Sydney will face Collingwood at the MCG on Friday night.