Walter Pandiani looks set for a move to Real Zaragoza after Deportivo La Coruna accepted a £2.7m bid for the Uruguayan striker.
The fee is more than the £1.7m Birmingham City were prepared to pay for Pandiani.
The striker spent the second half of last season on loan at St Andrews and the Blues were keen to make the deal permanent.
“The offer (from Zaragoza) has thrown a spanner in the works. Birmingham were holding out for as long as possible and waiting for Deportivo to panic and accept their offer,” his agent Francis Martin said.
“If Zaragoza had not come in, they could have probably held on until the end of August. But now it’s a case of giving Birmingham as long as possible to have a bid accepted by upping their offer.
“Walter will also want to think about things – which will give Birmingham more time – but it’s whether they want to pay that much, with wages on top, for a player approaching 30.
“But it’s also up to the lad whether he wants to reject the move and wait for Birmingham to increase their bid and give him his ideal move.”