Fremantle defender Garrick Ibbotson admits his team will be easily beaten if they underestimate the injury-hit Swans in Saturday’s qualifying final at Domain Stadium.

Sydney were dealt a huge blow on Tuesday when gun forward Lance Franklin was ruled out indefinitely while he deals with an ongoing mental health issue.

The Swans also confirmed Franklin had suffered a mild epileptic seizure last week that required hospital attention.

Franklin joins fellow stars Luke Parker (broken leg) and Kieren Jack (knee) on the sidelines, while defender Nick Smith (hamstring) could also miss this week.

In contrast, Fremantle will enter Saturday’s blockbuster clash feeling refreshed and ready to fire after coach Ross Lyon rested most of his stars last week.

The Dockers have been installed as hot favourites to beat Sydney.

But Ibbotson said his team remained wary of a Swans outfit renowned for their fighting spirit.

“They are a proud club,” Ibbotson said. “If we’re not on our game, we will get easily beaten.

“Just a couple of per cent here and there can make a big difference in an AFL game.

“Names don’t mean anything when we come to play a game of footy. We know that whoever is going to be on the park is going to be a formidable opponent for us.”

The absence of Franklin is a big boost to Fremantle’s chances of winning.

In last year’s qualifying final at Stadium Australia, Franklin booted two outstanding goals early in the final quarter to inspire his side to a 24-point victory over Fremantle.

His absence will heap more responsibility on Kurt Tippett, who has thrived in recent weeks alternating between the ruck and forward line.

Ibbotson will notch his 150-game milestone when he runs out against the Swans.

Although he has made a name for himself as a rebounding defender, Ibbotson has spent the past two weeks in the forward line to help fill the void left by injured stars Michael Walters and Hayden Ballantyne.

Ibbotson has managed just one goal from his two games in attack, and the experiment is likely to end this week when Ballantyne and Walters return.

“I was probably as surprised as anyone,” Ibbotson said of his reaction when told he was to play up forward.

“I haven’t done a whole lot of it.

“I have enjoyed it. It hasn’t thrown me.

“I may not play there again – who knows. That’s Ross’ decision. But at least I have had a go now.”