The Republic of Ireland international had been given permission by West Bromwich Albion to speak with the Tigers on deadline day with the KC Stadium club even flying him in from international duty on a charter plane.
However, a potential deal fell through with the Baggies suggesting Hull had altered the terms of the contract and manager Steve Clarke also making clear he did not want to lose Long.
Bruce admits he is still gutted at the near miss: "I'm obviously bitterly disappointed that we didn't get Shane Long.
"That would have been the icing on the cake in terms of the squad we're trying to get together. We thought at one stage we were really, really close.
"He left the headquarters of Ireland, he didn't get on a plane until 6.30pm, then I picked him up at Leeds Bradford Airport at 8.15pm for a medical at 9pm.
"It was being battered back and forward (between the clubs). I've seen that happen over days, weeks and months and I knew dialogue was going on, but we must have been there or thereabouts (on valuation) or why would they let him go on a plane? Why would he be doing a medical if there was no chance of it happening?
"But unfortunately it didn't happen. That's West Brom's prerogative, he's their player and they changed their mind for whatever reason.
"I'm sure Shane is as disappointed as anyone, stuck at our training ground, left high and dry effectively."