The 23-year-old defender initially rejected a contract offer from Millwall having been on trial with the club for three weeks following his summer release by the Cottagers.
But after Briggs had held talks with crisis club Blackpool over a possible move, the defender had a change of heart and on Friday put pen to paper on a one-year deal after more talks with Lions chief executive Andy Ambler.
“It was always going to turn around,” Holloway revealed.
“I switched off and told Andy: ‘Good luck with that.’
“I felt the kid worked so hard for me so I sat him down and showed him what I think he needs to do.
“I watched three games of his that I had one of our analysts clip.
“I could sit and watch them within 10 minutes. I watched three entire games.
“He chose a good game where he thought he played poorly and wasn’t quite sure.
“It was the first time that’s ever happened. He believes that potential to me is just a curse.”
He added: “People talk about you, you’re either as good as they think they should be or not.
“I saw some bloke put potential out of the water by believing in himself which was Les Ferdinand.
“Ray Wilkins said if you don’t look or feel the part you don’t do it.
“This kid could do whatever.”
Briggs will now face competition from fellow left-back Scott Malone, and Holloway also revealed he will look to nurture both of the Lions’ young full-backs.
He said: “I’ve got Scott Malone so I’ve just need to sit back and encourage the both of them.
“If they don’t show me respect they can get out of my office and get out of the club.
“I’m excited about Briggs wanting to play and wanting to be taught.
“I need him to step to the plate and take responsibility for everything he does.
“It’s the same with Magaye Gueye and hopefully we’ll get that right.
“If I can get the structure right and we all pull together - it’ will be quite exciting.”
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