Former Manchester United and England footballer Rio Ferdinand says taking up boxing gives him welcome focus after a period in which he has “been through quite a few things in my life”.
His wife Rebecca was 34 when she died from breast cancer in May 2015.
Ferdinand – who has three children – retired from football the same year.
“This is another way to channel that aggression, anger sometimes, and emotions into something I can be really focused on,” said the 38-year-old.
Ferdinand, who will be coached by former WBC super-middleweight champion Richie Woodhall, had initially said he was “aiming for a belt”.
But, in a news conference following the announcement, he said: “I’ve got the utmost respect for the boxing fraternity.
“It would be disrespectful for me to come here and say I’m going to win a title because there’s guys who have been doing it since they were five or six years old.
“First and foremost this is a challenge. Physically and mentally, can I get through the training and then go and get a professional licence?
“But I want to get past the first parts, get into the ring, take a shot, give a shot and go from there really.”
The Londoner insists he is going into this new sporting challenge with his eyes wide open.
He added: “I’ve spoken to professionals in the game, Richie more than anyone.
“I’m not disrespecting anyone and I know there will be moments when I question if I’m doing the right thing. I want to test myself in another sport.”
Ferdinand, who won the Premier League six times and the Champions League once, is attempting to follow former Birmingham City midfielder Curtis Woodhouse and former Crystal Palace forward Leon McKenzie, who became professional boxers after quitting football.
Source: BBC Sport