Yet Long, a part-time carpenter, insists he can nail Williams in front of BBC cameras.
He claimed: "Danny has had lots of easy opponents to pad out his record. I've had fewer fights but I've come up the hard way and I know what it's all about."
Indeed, Long has travelled far and wide in order to gain experience, sparring against respected Nigerian Duncan Dokiwari in Las Vegas and with former world amateur champion Georgie Kandelaki in Georgia.
Long has also shared a training ring with Williams. "It was about three years ago," he recalled. "I never felt overawed or that I couldn't handle him.
"Danny's taller, has much longer arms and a very good jab, so obviously I'm not going to outbox him.
"But I refuse to lose. I intend to stop him from boxing, force him backwards and take his heart."