Cobblers duo Shaun McWilliams and Harry Smith are both set for a lengthy period on the sidelines but manager Keith Curle will wait for a second opinion until giving a more detailed timeframe.
McWilliams and Smith picked up their injuries during the closing stages of Northampton's 4-0 defeat at Crawley Town on Boxing Day.
McWilliams damaged his knee and had to be stretchered off while Smith required nearly 10 minutes of treatment on an ankle problem before he too was carried from the field.
Both have since been sent for scans but although it's become clear that neither will be back any time soon, Curle says they cannot put a precise timeframe on their returns to action just yet.
"We've been dealt a blow with the news to Harry Smith and Shaun McWilliams, which is that neither of them will be back fit soon," confirmed Curle.
"They won't be back before the end of January and that means we're two first-team players light.
"They've had their scans and the scans have been reported on and there won't be an immediate return to training.
"There's still areas of swelling and repair that needs to be done so it's probably a case of leaving it until Monday or Tuesday next week.
"They'll then go for a second opinion and that's when we'll find out more because when you have a scan and there's swelling, it can be a bit distorted.
"So we're just waiting on a second opinion to find out exactly where they are and that'll be our starting point for rehabilitation."