Spireites forward Gary Roberts was substituted in the second half at Swindon on Saturday, and is today having a scan to discover the extent of his hamstring injury.
Roberts has had recurring issues with his hamstrings this season and Rodger Wylde, head of sports science and medicine, talked through the latest injury.
Wylde said: "The issue this time is with his other hamstring. It was his right and now it's his left hamstring.
"What happened was that Robbo was sprinting towards the touchline for a ball and then when he reached the ball he decided to back heel it.
"The hamstrings are a very complex group of muscles, when you're sprinting half of the muscles is contracting and half is relaxing, and in back heeling the ball he's completely changed the dynamics of the movement and his hamstring couldn't cope with it.
"An analogy of that could be travelling in a car at 60 miles per hour and then quickly trying to put the car into reverse, which causes incredible strain on the area."
Wylde explained the diagnosis process that Roberts will now go through before the Spireites' medical team can start his recovery work.
"He's having a scan today and we'll see if it's a grade two or a grade three hamstring strain," Wylde explained. "After the scan we'll know more about how to progress with the injury.
"In all likelihood we could be looking at six weeks of recovery work, if it's a grade two injury, but we'll be able to make a better recovery schedule once we've received the scan results."