Boss Stuart Pearce has hinted as much. But his latest revelation about the 28-year-old suggests Forest may have been left with one less option in dealing with Assombalonga's absence.
Indeed, Pearce has admitted that Nottingham Forest wanted to loan Blackstock out earlier in the Championship season.
The striker rejected an offer from Sheffield United but it sems the club were more eager for him to leave on a temporary basis than he was to leave - the boss might count his lucky stars that he didn't now that Assombalonga is suspended.
"I believe he is ready. Three or four weeks ago we felt he might have to go out and get that fitness on loan," Pearce told reporters.
"Since that time, he has worked his way closer and closer to the first team. He has come off the bench a few times. He had a few efforts at goal at Birmingham as well, after he had come on.
"We would not put him out on loan now, if that was possible. Put it that way. He has his tail up."
Forest host Charlton at the City Ground tomorrow afternoon at 3pm.