Geelong veteran Tom Hawkins is out for up to eight weeks but remains confident a foot injury won't end his decorated career.
The Cats say their games-record holder will miss six to eight weeks because of an atypical mid foot joint and ligament injury in his left foot.
The 35-year-old is uncontracted beyond this season and Geelong have nine games remaining before any finals campaign.
"Tom has already been in the club today and commenced his off-foot training," Cats football manager Andrew Mackie said.
"He'll remain in a boot for the next couple of weeks before progressing based on clinical signs.
"Tom is in a positive and optimistic mindset and we are confident he will give himself the best chance to have an impact later in the season."
Hawkins on Monday said he was "pretty optimistic" about returning.
"I'm always pretty optimistic about life in general," he said.
"Once I find out the information I will put together a little bit of a plan.
"I can respect that there is interest with age and current form, but it (whether it's the end of his season or career) is far from my mind at the moment."
Geelong are no certainties to reach the finals with the club sliding to seventh after six losses in their past seven games.
Beyond Saturday night's clash with Essendon, the Cats meet Hawthorn, Collingwood and the Western Bulldogs in a season-shaping month.
Fremantle's stocks have also taken a hit with skipper Alex Pearce sidelined for a month by a broken arm.
Pearce was hurt in last Sunday's win against Gold Coast, landing awkwardly on his left forearm in a marking contest.
Scans have confirmed a fracture and the 29-year-old will have surgery later this week.
"Obviously disappointing to lose Alex for the next few weeks," Fremantle's football manager Joe Brierty said.
"He has had a fantastic year down back to date and his leadership has been second to none."
Pearce has been the backbone of the fifth-placed Dockers' defence, which has conceded second-fewest scores, behind ladder leaders Sydney, this season.
The Swans host Freo at the SCG on Saturday afternoon.
Meanwhile, Port Adelaide ruck Ivan Soldo will miss a month because of ongoing knee soreness.
Soldo, who returned to AFL ranks a fortnight ago after arthroscopic surgery in late April, is suffering scar tissue irritation.
His teammate Jase Burgoyne has a hamstring strain and will be sidelined at least a fortnight.
