GUN ESSENDON swingman Cale Hooker will miss at least the first month of the season after suffering a calf strain.

The 30-year-old had been nursing a hamstring injury but was completing his last training session before a planned return against Geelong in a JLT Community Series clash on Thursday at GMHBA Stadium when he was hit with another soft-tissue problem.

"He's picked up a soleus injury (which is) a calf strain that will cost him six weeks. Cale had been doing everything right. He's a professional," Bombers fitness boss Justin Crow told essendonfc.com.au.

"It's disappointing news for us and him but we'll have to get back to rehab and keep building him up ahead of an early-season return."

The Bombers face Greater Western Sydney in round one before coming up against St Kilda, Melbourne and Brisbane.

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Star recruit Dylan Shiel is set to face the Cats after copping a left quad corkie in his first outing for the red and black against Carlton.

"We all saw Dylan leave the ground after getting that knock to his thigh, we iced it up straight away (on) match day," Crow said.

"He's a professional, so he's been doing all of the work required to get that right.

"He trained and moved quite well, so we'll be expecting him to be available for the match."

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Joining him will be electric small forward Orazio Fantasia, who didn't face Carlton as he dealt with a corkie of his own.

"'Raz' trained really sharply in our main session and he'll be available on modified game time this week," Crow said.

Rookie Tuth Jok, also known as Tom, was concussed in the last quarter against the Blues and has suffered after-effects.

"Tuth's had a few headaches after that (incident)," Crow said.

"The way he's tracking, he's showing improvement from the head knock, but we're not expecting him to be available in time for the next match."