Steve Bruce has voiced his frustration after being forced to abandon his bid to sign Mohamed Kallon.
The Sierra Leone striker has been training with Birmingham for the past ten days following his release from Monaco.
Bruce had been keen to sign Kallon but decided not to pursue the matter after learning it would be difficult to obtain a work permit.
Bruce told Sky Sports News: "He needs a work permit and obviously, with him not being an international, you have to go to appeal.
"But it was one of those impossible situations.
"I've known him for a little while because I tried to sign him about four or five years ago.
"He came to train with us and he's made no secret that he would like to play in England.
"But with the homework we had done, we didn't think it would be possible to get the work permit."
Bruce is nevertheless happy with the squad he has at his disposal for the clash with Bolton this weekend, after reporting no new injury concerns.
"We've had 21 players train today, which is the first time in a long time that we've had a fully fit squad," he explained.
"We expect Damien Johnson, who's been out with a hamstring injury, to return on Monday, so at the moment we've got a fully fit squad which we're very pleased about."