A cautious Harvey said the club would have a more accurate time line for Barlow's return from a broken leg when the prolific ball-winner joins in full training within the next fortnight.
The coach was adamant Fremantle had not ruled out a return within the first eight rounds and tipped the 23-year-old to reproduce the stunning form that saw him collect more possessions in his first 12 AFL games than anyone before him.
"We've got the bye in round six, so we'd like to think that somewhere in and around those areas he'll be available for selection, whether it be WAFL or AFL," Harvey said.
"[But] you only need a small hiccup with that type of injury and you can be back another couple of weeks.
"All I can say is that he's really stepping up his running. I would envisage that in the next couple of weeks he will join in training and then we'll be able to assess things more once he joins in football training.
"Why it's hard to give an estimate of when he's playing is because of all the soft tissue around his leg that he may have issues with in his comeback, not necessarily with direct injury."
Harvey said technology and Barlow's unique running gait would help him return to his best after suffering the broken leg in round 14 last season.
"He wasn't an up-on-his-toes jumper or anything like that, [so] I think he'll overcome it quite quickly," the coach said.
"His running gait - he looks like he runs with a limp anyway.
"You look at Chris Newman and those sort of guys, with technology these days I don't think it will be an issue."
Barlow joined roughly half of Fremantle's squad, including Stephen Hill, Hayden Ballantyne, David Mundy, Nat Fyfe and Matt de Boer, for a light training run on Monday morning.
The group, all of whom are yet to play this pre-season, took part in a series of 40m run-throughs, with Mundy and Fyfe appearing the most advanced ahead of Fremantle's NAB Challenge clash with the Western Bulldogs in Bunbury this Saturday.
Harvey, who reiterated that dynamic midfielder Hill and goalsneak Ballantyne would be ready for round one, said their limited game time was not a worry, particularly with Ballantyne.
"It's probably a good thing that he hasn't been able to do a lot, because he tends to push it to the limit a lot," the coach said.
"He and Hill and these sorts of guys don't need a hell of a lot of training. They're lucky that their equipment brings them up really fast, so it's not a huge issue for us."
Fremantle has lost talented young midfielder Anthony Morabito (knee) for the season and Garrick Ibbotson (ankle) for the opening rounds. Roger Hayden is recovering from foot surgery but Harvey ruled out placing the defender on the long-term injury list.
Michael Barlow is a $456,200 midfielder in the Toyota AFL Dream Team competition
