Darren Ferguson says he has inherited an ‘unbalanced’ squad.
The Scot acknowledged this week that his playing staff is top heavy with midfielders and attackers.
And, after watching his side ship six goals in the last two games without reply, Ferguson says he has stepped up his search for defensive reinforcements.
Prior to Tuesday night’s defeat at Millwall, Ferguson said: “To assess what I’ve got in just a few games would be slightly unfair.
“But, in saying that, I think we’re short on defenders. You can see that.
“I think we’ve only got two centre halves fit.
“Then you’ve only got one right back in Mitchell [Lund].
“You’ve got Aaron [Taylor-Sinclair] who can play if there’s three centre backs and at left back, and Cedric [Evina].
“So you’re unbalanced because you’ve got a load of midfield players and a load of attackers.
“We just need to get the balance right on that.
“Of course I want to assess them and give them all an opportunity,” he added.
“It’s up to me to challenge them. I’ve got to be challenging them every day and that’s what I will be doing.”
Ferguson went with a back five of Mitchell Lund, Luke McCullough, Andy Butler, Aaron Taylor-Sinclair and Cedric Evina against Millwall.
Rob Jones is back in training, while fellow centre back Gary MacKenzie is currently out injured.
“A job’s got to be done,” said Ferguson.
“I’ve been brought in to do a job and I can either do it with the ones I’ve got or without them.
“That’s up to them.
“They know that, they’ve heard it from myself. A job’s got to be done. It’s as simple as that.”