SEIZING your opportunity when it's presented is a mark of a person's desire to succeed.

Melbourne's James Magner, who has waited an age for his chance at the top level, isn't about to let it slip through his fingertips.

The 24-year-old notched 20 possessions, eight tackles, seven clearances and 86 Dream Team points as the Demons fell 18 points short of an upset over St Kilda at the MCG on Saturday night.

After shutting down Western Bulldogs skipper Matthew Boyd the week before, Magner was charged with the job of restricting the Saints' prime onballer Nick Dal Santo.

In the first half he was relentless, getting inside at stoppages and getting the ball on to his boot.

He kept driving Melbourne forward, and, as the game went on, drove himself.

Magner battled on through pain and suffering, first receiving a nasty gash that required stiches under his left eye in an off-the-ball incident with Saint Leigh Montagna.

If that wasn't enough, his knee caved in during an awkward pile up between teammate Luke Tapscott and Saints midfielder Jack Steven.

Magner has made an immediate impression at the Demons, ranking third in kicks, second in handballs, second in disposals and second in tackles after round five.

In the pre-season Magner, the son of Irish immigrants, was at the club before everyone else every morning striving to win a spot on the senior list.

He was elevated off the rookie list before round one and kicked two goals with his first two kicks on debut, and earned the reputation of being a strong competitor.

Even when he looked to have been slowed by injury against the Saints, he returned to the fray, keeping it simple and continuing to trap the ball.

Sydney Swans premiership coach Paul Roos said on Fox Footy on Saturday night that mental toughness to play through injury is why 300-game stars Adam Goodes and Simon Black are so highly respected.

Magner still has a long way to go to reach those sorts of high standards, but his determination and grit are sure to carry him far.