Long appeared set to make the switch to Humberside in the summer, after Albion signed Nicolas Anelka, Stephane Sessegnon and Victor Anichebe.
Talks took place, but a deal failed to materialise and Bruce has indicated he may well try again to sign the Republic of Ireland international, who started up front in Saturday's 1-1 draw with Hull City.
The Baggies are currently without a manager after sacking Steve Clarke following the 1-0 defeat to Cardiff, with Keith Downing in charge in a caretaker capacity until Clarke's successor is appointed.
Bruce will keep an eye on whether Long is in the new manager's plans - and could rekindle his interest in the 26-year-old if not.
"A new head coach will come in and who knows?" said Bruce.
"If he became available, then I would love to try to do something. But we thought we had a deal on deadline day and it didn't quite happen.
"We'll see what the situation is, but we'll respect the fact that he is a West