STEFAN Martin said he was passive against the Western Bulldogs last week, but was adamant it had nothing to do with the concussion he received the previous week.

Martin was knocked out in round four by Gold Coast defender Steven May and fronted up against the Bulldogs seven days later.

Speaking on the eve of his 100th match, the Brisbane Lions ruckman denied his struggles against the Bulldogs were a result of any lingering affects from the heavy hit.

Match preview: Brisbane Lions v Sydney Swans

"I was fine. It was just one of those days where I wasn't sharp enough or hard enough to have a good game," he said.

"I was very passive, I was ball-watching a lot, not aggressive, which are the things I've modelled my game on the last few years and I didn't do any of it on the weekend.

"(I've got) Another chance this week to do those things."

Martin said rather than the concussion making him more conscious of long-lasting effects, he was now confident he could absorb heavy hits.

He said the fact he got straight back to studying two days later was better than any test the club could give him.

Playing the Sydney Swans at the Gabba on Sunday marks a milestone for Martin that has been nine years in the waiting.

Lions coach Justin Leppitsch believes the 29-year-old – who was a joint best and fairest winner last year - is just entering his prime.

"I reckon he's got another 100 in him," Leppitsch said.

"Stef's got the sort of body that can go the distance, I think. He looks after himself and is highly professional.

"Stef can get to 35 (years old) easy and knock over (another) 100 pretty quick."

As has been the case all season, Leppitsch said the key to being competitive against the Swans would be the Lions' contested ball numbers.

They were minus 51 against the Bulldogs last week, a stat Leppitsch was generous in describing as "poor".