Former Atletico Madrid midfielder Luccin chose Real Zaragoza over Birmingham and Bruce said: "He has got a couple of caps for Spain. It was one of those where it looked earlier last week he was going to Benfica.
"It didn't quite happen so we jumped on the back of it. We were disappointed with what happened with Peter Luccin in missing out when it looked as if it was a done deal.
"That left us with little time but Borja is a quality player who will be a good asset for us."