Karl Robinson is struggling to bring in players to bolster his squad with less than three weeks before the season starts.
Only four players - Ed Upson, Paul Downing, George Williams and Nicky Maynard - have signed this summer, while outgoings are in double figures.
Having been outbid for a number of targets, Robinson admits he has been turned down many times this summer.
And with the season opener against Shrewsbury looming on August 6, Robinson is aware time is running out.
“We’re looking but we’re coming across a lot of closed doors,” he said. “It has been a frustrating few weeks.
“There is a slight fear because the numbers aren’t where we want them to be, but it’s important we find these players in a matter of days, rather than weeks now.
“We’re getting criticised, but we’ve got to get the right players.
“We did it all early last year, and got criticised for the players we brought in. It’s important we get the right people in, and we’re working hard to find them.
“It has been hard because we’ve been relegated and our aspirations on what we want and what we can get aren’t quite matching up.”
While the squad is desperately light on numbers though, Robinson says his existing players are being kept in the loop with the movements behind-the-scenes as they battle to bring new faces in.
He said: “The players have been informed all the way through. The players know our transfer policy, and they know we’re waiting for the right ones.
“We need a striker and two wide players because we’re very short there. And with Kyle (McFadzean) leaving, we need a new centre half as well.
“There is a lot of work still to be done.”