Amir Khan admitted it was he who told his corner to pull him out of his world title fight.
Khan was dropped in the first round against Terence Crawford but recovered to work his way back into the fight.
The Brit was hit with a low blow in the sixth round but was struggling to recover.
Khan was allowed five minutes to do so but told trainer Virgil Hunter he could not continue.
The beaten man said: "I want to apologise to all the fans; the fight was getting interesting.
"Terence is a great fighter, I’m not taking anything away from him but it was a shot below the belt and I could feel it in my stomach and I couldn't continue.
Amir Khan quits world title challenge against Terence Crawford due to low blow
"I'm a warrior and I wouldn't give up a fight like this. I could feel it in my stomach and my legs kind of seized and Virgil asked me how I was feeling and I said I couldn't move.
"I couldn't continue, I’m not one of those fighters who quits but I was hit with a hard shot below the belt.
"I’m going to go back to the drawing board and talk to my family and see where I go from here."
Hunter, who also revealed Khan had been struggling with an injury to his right arm, denied Khan was looking for a way out.
He said: "He indicated to me that he was hit in the test and it took the life out of him - I have to take his word for it.
"I don't think he was looking for a way out of the fight. he started picking up on Crawford's rhythm and we don't know how it would have played out. He indicated he was hit wit a bad shot."
