Cobblers midfielder Alan McCormack has an outside chance of making the squad for Sunday's FA Cup tie against Burton Albion, but it's less good news for Shaun McWilliams and Harry Smith, who both face at least two months out.
McCormack was substituted early in the second-half at Crawley Town on Boxing Day and then missed Northampton's draw with Cheltenham and the win over Stevenage on New Year's Day.
Curle revealed after the Cheltenham game that the 35-year-old had gone for a scan on an unspecified injury, however he provided a more encouraging update on Friday.
"Alan's back training on the grass and Friday and Saturday will be another opportunity to get more training into him," said the Town boss.
"We'll then make an assessment on him before we name the team for the Burton game."
Smith and McWilliams will definitely miss Sunday's cup tie and could well face up to three months out after picking up serious injuries during the defeat to Crawley.
Curle added: "Shaun and Harry are long-term injures. It's going to be eight, 10, 12 weeks and that's only the initial diagnoses because the injuries still need time to settle down.
"Neither of them at the minute need operations which is pleasing, but the first three to four weeks of their recovery now is vitally important.
"That can set a trend for how quickly they can get back fit. The injuries are ankle and knee."