‘The Special One’ was halted late by the American, who also took his welterweight world title, just eight months after Gennady Golovkin handed him his maiden defeat back in September.
Eye problems in both bouts, each requiring surgery, had Brook thinking hard about whether to fight again and the Yorkshireman says he still has some decisions to make before any comeback announcement can happen.
“(Retirement) did occur to me,” Brook told Bob Westerdale of The Sheffield Star in an interview this week.
“After the Spence fight, I was in hospital having a scan, finding out my eye had been broken, my Mum and Dad were talking about me retiring. I thought about my career, how I started off against Peter Buckley, how everything had flashed by and wondering where all that time had gone.
“I was thinking about whether to retire especially after the camp I’d had, it wasn’t the best. I had been ill three times during the run-up. But I am going away to clear my mind and maybe when I come back I’ll change some things. Maybe big things.”
On the possibility of moving up to super-welterweight, which many believe would be the 31 year-old’s ideal weight class on the back of year’s being tight at 147 pounds, Brook added: “At the moment I don’t know what is going to happen. Like I say, I will be thinking about a lot of things.”
Brook also told Westerdale making the lower limit “killed him” but that he wasn’t against staying put.
“If the right fight came along it would be something I’d have to think about.
“(At 154) They are bigger guys, taller, stronger and it is going to be tough to go that extra gear,” he said.
One of those options at 147 would be a mammoth collision with Amir Khan, although both sides still seem to miles away from an agreement despite limited options for the respective boxers.