FREMANTLE'S new-look forward line has been dealt a hefty blow ahead of round one, with star goalkicker Hayden Ballantyne likely to miss up to a month of football due to a left hamstring injury.

Ballantyne walked slowly from the ground during the third quarter of the Dockers' 21-point JLT Community Series win over Carlton on Friday night and went straight to the rooms. 

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The injury occurred after he kicked, stumbled and fell over in the centre square.

Speaking post-match, Dockers coach Ross Lyon said the prognosis didn't look good for the club's 2014 leading goalkicker. 

But, in better news, defender Cam Sutcliffe (ankle) should be back training next week after sitting out the last three quarters.

"Cam will be fine, he'll be slow early in the week and then he'll get going," Lyon said.

"Hayden is disappointing, he was really humming along and looking cherry-ripe.

"We need the scans, so I don't want to pre-empt anything, but he's saying it feels like a relatively normal hamstring, so (probably) 3-4 weeks (on the sidelines)."

Watch: Ross Lyon's full post-match media conference

If Ballantyne misses four weeks, he could be out for round one against Geelong, the round two clash with Port Adelaide and might also be touch-and-go to face the Western Bulldogs on April 8.

The 29-year-old's injury was the low point on an otherwise promising night for Fremantle.

Superstar skipper Nat Fyfe dominated with 38 disposals, plus a goal and a supergoal, while recruit Cam McCarthy slotted six majors in his third game back from a year out of the game.

"I'm really pleased for him. I said he got on the end of a few, but League football is about hard work and he hasn't missed a session during pre-season," Lyon said of McCarthy.

"He's a tough kid who trains and works and is earning respect the right way."


Dockers fans also got their first look at top-10 draftee Griffin Logue, who had two shaky moments where he dropped a mark and gifted away a goal, but also booted a booming supergoal from 11 touches in a promising debut.

"I think Griffin Logue had a good taste of the intensity and the pressure and step up from WAFL level, really," Lyon said.

Despite a winless pre-season campaign, Carlton coach Brendon Bolton was confident his side is building towards the season-opener against Richmond. 

The Blues have played youngsters during the JLT Community Series, and continued to experiment with young backman Jacob Weitering in attack, where he impressed against Freo with his aerial presence.

"We used Levi (Casboult) a little bit in the ruck tonight, so it just gave us another target there," Bolton said.

"It's all part of his development – we'll continue to use him at both ends like we've said – but JLT is always that chance to do it.

"We think we've got more flexibility, but I think I've said a few times now that we'll keep growing Weiters as a defender and use him up forward as necessary because in time we want him to play both ends."

Former Giants small forward Jarrod Pickett was another who caught the eye with three classy goals.

"He's growing as a footballer. It's only early days, but we think he can use the ball well, he's got good speed and he's adapting to the way we play the game," Bolton said. 

"We liked some of the signs, though."

WATCH: Brendon Bolton's post-match media conference

Importantly, gun midfielder Patrick Cripps got through his second match since a long-term back injury, racking up 26 touches from about 60 per cent game time.

"He's a bull. He had a real crack," Bolton said.

"It just shows that mindset in football is really important and he's determined to push his body to give himself the best prep for round one given he's been interrupted in pre-season, so (that's) good willpower."