Darlow was recalled from a loan spell at Walsall by boss Alex McLeish and then handed his full league debut for the club against Peterborough, helping McLeish gain his first win since taking over at the City Ground.
Darlow got his chance after McLeish informed long-time number one Lee Camp, whose contract is set to expire in the summer, that he could leave Forest this month.
McLeish had previously stated that the 22-year-old would play while he searched for an experienced keeper to replace Camp.
But after signing Khalid Al Rashidi this week, the Scot revealed that Darlow and the Kuwait international will battle it out for the number one spot.
"The only keeper coming in will be Khalid, we have successfully secured a work permit for him," said McLeish.
"He will be back-up to Karl Darlow until he acclimatises, then it will be a big fight between the two guys."