The 24 year-old, who came through the rugged Scouser on a majority decision at the Echo Arena, revealed the injury to fledging boxing channel BoxNation and admitted that he took a gamble with his world title status on the night.
“We had top keep it majorly quiet,” explained the Cefn Forest fighter.
“I did it when I was training in London two weeks before the fight. I did six rounds with George Groves and then another six with Chris Eubanks’ boy and in the 11th he caught me on the back and cracked a rib.
“I finished off the 12 rounds and didn’t show any pain, but I had a week of sparring back home planned with Sam Sexton, a heavyweight, which I had to cancel because I could not take a shot to the rib because I was in so much pain.
“I saw the doctor and the physio and they both said the only thing was rest.
“My dad, girlfriend, Adam Booth and Groves, who had been there when it happened, were the only ones who knew and I also told Frank Warren.
“I gave it a couple of days and in the end I said, ‘bugger it – let’s gamble on him not throwing any body shots with the left’.”
Cleverly eventually got through the bout with only one or two shots hitting the affected area although It may have been a different story for the Welshman though if Bellew was a known body puncher and he may have postponed the fight.
The undefeated champion is now setting his sights on a unification bout with WBA belt holder Beibut Shumenov or a high-profile match-up with Bernard Hopkins in Wales after fighting outside his home country for the past four years.