Republic of Ireland striker Long was set to join the Tigers in a deadline day switch from West Brom on September 2, only for the Baggies to pull the plug when their own pursuit of Romelu Lukaku fell through.
That left Long sitting with Bruce at Hull's training ground in Cottingham when both men realised the transfer was off.
But Bruce did not waste his time with Long, laying out his plans for Hull and planting a seed that came to bear when West Brom again agreed a fee of around £6.5million this month.
"It was a weird one (in September). I think there was 10 hours from finding out about the deal to get it done and it got pulled a the last minute," Long said.
"It was a strange situation to be in but these things happen in football.
"I tried to be as professional as I could be. I was a West Brom player and I think anyone there would tell you I gave my all on the pitch and trained hard every day.
"But it was hard to try and get it out of your head.
"I think it was always in the back of my mind that West Brom wanted to sell up and I was lucky that a club like Hull were interested.
"After meeting the manager (Bruce), he left a good impression on me and I wanted to play for him.
"He was just talking to me about the club, the players coming in and how I was going to be a part of it.
"When a club is agreeing to sell you, for me anyway, you want to go.
"Once the transfer window opened again, it was inevitable something was going to happen sooner rather than later and I got the deal done."
Long, who has shaken off an ankle complaint and has been told he will play some part against Palace, will now look forward to forging a partnership with fellow newcomer Nikica Jelavic.
The Croatia striker was brought in from Everton for a fee that could rise to £7.5million should Hull avoid relegation, taking the club's spending to £14million this month - a serious gamble that will require Premier League safety as a minimum pay-off.
Palace boss Tony Pulis has said the double deal has effectively guaranteed Hull's safety and, while Bruce took those words with a pinch of salt, he is desperate to prove them right.
"I'm sure Tony was having a little bit of fun, having a little bit of politics to try and get a few new players in of his own," said Bruce.
"And I hope he's right because that's why we've done it, bringing the two of them in,
"It's just like we acted in the summer to make sure we were strong and competitive.
"What we have we have done is give ourselves a wonderful chance of staying in the division. The more good players you've got the better chance you'll have."