Bendtner's injury has come at a particularly awkward time

The on-loan Arsenal player is out for up to a month with an ankle injury and Sullivan says he buy a replacement.

"We don't want the club in debt because it would never recover," he said.

"But at the same time, we are looking to buy players to help the team. We accept that the injury to Nicklas means we have to buy a striker and we will."

There is plenty going on behind the scenes. We are doing all we can David Sullivan

Manager Steve Bruce has shown interest in Luton's Rowan Vine, who is thought to be keen on a move.

They also hope to sign another on-loan Arsenal player, Sebastian Larsson, on a permanent basis.

Sullivan has given manager Steve Bruce money to spend to get the Blues back into the Premiership at the first time of asking, but has warned the money has run out.

"We are �5m overdrawn, in breach of our overdraft limit with the bank," he said.

"It does my brain in when people say 'where has all the money gone?'. We've spent it.

"There are hidden extras fans don't know about like pay-offs to get rid of players, agents' fees etc. Our gate receipts are way below covering our wages.

"We will try to bring in the best we can get. There is plenty going on behind the scenes. We are doing all we can."