Blackstock, 26, was nursing a hamstring problem prior to Saturday's Championship fixture at the City Ground, and the player had to be withdrawn after 34 minutes.
With hindsight, Reds boss Billy Davies admitted he should not have played Blackstock. But a shortage of strikers forced the Scot's hand.
Forest now face an anxious wait to see if he will be fit for the weekend trip to automatic promotion chasers Hull.
Davies said: "I should not have played Dexter Blackstock because he had a slight hamstring problem.
"I probably shouldn't have had Billy Sharp on the bench but I asked him if he could give us 20 minutes if we needed him to, given that he still had this chest infection.
"So, we have lost Darius Henderson to a knee problem, Billy Sharp has a chest infection and Dexter Blackstock has a hamstring problem. And Marcus Tudgay (broken collarbone) is still unavailable.
"We knew that Dexter was a risk. We will look at him, and the other players, this week. Hopefully, we can get these players rested and get them back before the next match. That is the one we will focus on, nothing else."