Lower didn't require surgery after the incident - in which an opponent's knee collided with his left leg - but the club has been conservative with his rehabilitation.
Club doctor Con Mitropoulos said Lower had only resumed twisting and turning drills on Friday and needed to get through a full week's training to be considered for selection.
"It was such in a good position we just let it heal on its own," Mitropoulos said of the fracture.
"Bones take about six weeks to get pretty strong [so we've had] an extra week just for insurance.
"The risk of it coming apart is very slim. Even if he had a major operation with plates and screws, he would still be back in the same time."
Mitropoulos said Lower's greatest challenge was to now avoid the soft-tissue injuries that could follow a major injury.
Though he has been running for more than two weeks, the 22-year-old still has some way to go from a conditioning perspective.
"If you think you can bring them back sooner, you come undone because they tear a calf or a hamstring," Mitropoulos said.
"You only need to look at him to see the difference in his calf sizes.
"The key with him is to get his calf strength up over the next few weeks.
"Part of that calf strength is also running around and playing, which gives him the ability to fatigue his calf and get back to his normal self again, which probably will take another month."
It is likely that Lower will play for North Ballarat's reserves side against Casey Scorpions at Eureka Stadium on Saturday.
Before the injury, he had enjoyed a strong pre-season with the view that he could finally secure a regular spot at AFL level.
Lower's nine games last year included the victories over St Kilda and Port Adelaide in rounds 21 and 22, after which he returned to North Ballarat for a place in the club's eventual premiership side.
