The 23 year-old, predominantly a journeyman, shared the ring with the likes of Anthony Ogogo, Callum Smith, David Brophy and Liam Williams, having only been stopped by the latter in 64 contests.
Due to a bleed on the brain suffered by brother Nick in his British title bout against Chris Eubank Jr. last month, Dan has decided that it would be unfair of him to put his family through further heartache after his elder sibling spent six days in a coma.
“I thought my brother was dead: just that thought,” Blackwell told Press Association Sport.
“It wasn’t me worried about myself, it was me thinking ‘God, if I was ever in that position to put my own family through this…
“The worry of me thinking ‘He could be dead’; it was how my family would be feeling. I wouldn’t ever want to put them through that.
“What I went through with Nick was horrible.
“My mum has never liked me and Nick boxing, but I’ve always done what Nick’s done.
“I don’t want to be still in boxing, fighting and all the rest of it, knowing he can’t fight. With him, I don’t think it’s sunk in yet that he’s not fighting anymore,” he added.
Nick and Dan are well respected in the sport as upstanding and honest young men, so both will be sorely missed as they hang up their gloves and move on with the lives.
WBN wishes them both and their families well…