The 27 year old central defender, who has joined The Reds on emergency loan from Norwich, had a similar spell under O’Driscoll earlier in his career.
Ward goes straight into the Forest squad for tomorrow’s game against Barnsley at Oakwell (kick-off 3pm).
And O’Driscoll told us: “I had him at Doncaster so I know his character and he did really well for me.
“He has been part of a promotion winning team so he has got that mentality and he knows what it takes in the Championship.
“He was keen to join us and understands the situation, that we’re a bit light defensively but the lads have done really well so there are no guarantees.
“He will fit into the group character-wise and one or two of the lads already know him, which will help him. He will give us something we need.”