Belfast's Frampton weighed in marginally heavier than his opponent on Friday at 129.9lbs, with defending champion Herring stepping on the scales at 129.4lbs.
Ex-US Marine Herring has held the WBO belt since 2019 after beating Masayuki Ito.
He is five inches taller than Frampton at 5'10", with a 72-inch reach compared to the Northern Irishman's 65-inch arm span.
Both fighters have two losses on their records. Of Frampton's 28 wins, 16 have been by knockout.
Herring has won 22 of his 24 bouts, 10 by knockout.
The former bantamweight and featherweight champion first fractured his hand in the summer of 2019.
He required surgery on both hands following a unanimous win over Tyler McCreary that November, which was his first fight since losing to Josh Warrington in their 2018 IBF featherweight title class.
Belfast's Frampton weighed in marginally heavier than his opponent on Friday at 129.9lbs, with defending champion Herring stepping on the scales at 129.4lbs.Ex-US Marine Herring has held the WBO belt since 2019 after beating Masayuki Ito.He is five i
Carl Frampton: "I said I would retire if I lost this fight and that is what I am going to do. I want to dedicate my life to my family now. Boxing has been good to me. I want to go home to my beautiful wife and kids and dedicate my life to them.
"I was just beaten by the better man. Perfect game plan and I just got beat. Zero excuses. I had an amazing camp and came into it to win it. I got beaten by the better man."
'I was beaten by the better man'....Carl Frampton: "I said I would retire if I lost this fight and that is what I am going to do. I want to dedicate my life to my family now. Boxing has been good to me. I want to go home to my beautiful wife and kids