The South Yorkshire pair, who are usually on friendly terms, will go head to head for the vacant English super-lightweight title in Manchester on Saturday.
'Thunder', who trains at the Steel City Gym in Darnall, has finished six of his seven professional contests inside the distance. The 24-year-old former Team GB star kept his six-fight KO streak running last time out when he retired Birmingham's Ishmael Ellis in three rounds on the Josh Warrington vs. Mauricio Lara undercard.
He told Matchroom Boxing: “I think I can knock him out. We’ve both sparred, and we both know how those spars went.
"Don’t get me wrong, Lee is tough and he’s strong. He’s going to try and take me into the deep waters in those later rounds. No disrespect to Lee, I think he’s a great fighter in and out of the ring, but I feel confident that I can get him out of there.”
Appleyard, from Bramley in Rotherham, is nine years Smith’s senior and a former English lightweight champion who has boxed 100 more rounds as a professional than his hotshot opponent.
He told The Star last month: “The best version of me beats the best version of Dalton. I believe it’s my time. If he beats me, he’s as good as they say he is.
“Dalton is definitely the best person I am ever going to go in with but he’s a seven-fight novice.”
The 33-year-old has been trained by Stefy Bull ahead of his first bout in 18 months alongside Terri Harper, who was due to fight on the same card but had to withdraw due to the recurrence of a hand injury.
Smith vs. Appleyard is likely to be first up on the night, with Doncaster’s Jason Cunningham also set to take on Sheffield-based Gamal Yafai - who will represent Team GB at this summer’s Tokyo Olympics - for the European Super-Bantamweight title.
Smith added: “I’m maturing and I’m punching harder. I’ve always been able to carry power but now I feel like a different animal. I think it’s a perfect fight for me.”