The London 2012 gold medal winner was beaten on a split decision in California on Saturday night against the Venezuelan champion. And the 29-year-old Englishman revealed his father Bernard, who was diagnosed with cancer in 2014, died aged 58 in Hull while he was in the United States.
Campbell kept the news to himself as he did not want his opponent to know before the fight.
“If someone had found out I would have denied it. I didn’t want Linares’ camp thinking it was a weakness. I didn’t want them thinking I was hurt,” Campbell told BBC Sport.
“The only thing that kept me going is I know what my dad would have wanted for me. To fight and to win. I probably cried once a day. I had to try and shut feelings off. After the fight I had a good cry.”
In the fight, Campbell recovered after being knocked down in the second round. Scot Victor Loughlin scored the contest 115-113 to Campbell, but the other two judges had Linares winning with scores of 115-112 and 114-113.
Campbell added: “I had a lot to deal with in the last two weeks. All the people writing me off, the negativity and in the background my dad died. I think I shut a lot of mouths and I thought I actually won the fight. I think I did my dad proud, I think we showed how tough we are.
“It was hard for me. I was close to my dad. All the family was together at home and I was on my own, no one around me. I’m glad people had comfort at home but I feel bad because I wanted to be with my dad. I’ve been telling myself he went because he wanted to be with me.”