Ormerod had a goalless spell on loan at Leeds earlier in the season but impressed Blackwell enough with his attitude and performances.
The ex-Blackpool forward was recalled to help Southampton through an injury crisis but with the return from injury of James Beattie and Kevin Phillips and the emergence of youngster Dexter Blackstock, Ormerod has found himself back on the sub’s bench.
Deane limped off with a hamstring injury during the 2-2 draw with Watford on Wednesday, just days after hitting four goals against QPR and may be out for up to six weeks.