With a modest 13-0 record - and all but one of them coming in the super-featherweight division - Walsh is being given little chance against a 29-year-old Scot who is in the form of his life.
But Burns will treat his opponent with the utmost respect as he targets future appointments with fellow light title holders Antonio DeMarco and Miguel Vazquez.
"People are writing Liam off saying he's got no chance, but I can't look at it like that. This will be trickier than people think," he said.
"Liam is a good boxer, but I've had these big unification fights dangled in front of me and that will give me a bit of extra incentive.
"Right now though Liam has my full attention. I'm training for a 12-round war. He's got nothing to lose and has been performing well.
"Liam got offered the fight and jumped at the chance and it was the same when I boxed Alex Arthur (Burns lost on points in 2006).
"I'd only had 13 fights and he was British, Commonwealth and European champion."
Burns thrilled the nation with the manner of his victory against Mitchell in what was viewed as a genuine 50-50 fight, not the one-sided demolition that transpired.
Fans eager to see him against big names such as DeMarco, Vazquez, Brandon Rios and Robert Guerrero were thus disappointed when Walsh, the 26-year-old from Manchester, was unveiled as his 38th opponent.
The reputation of Burns, who lost twice earlier in his career against Arthur and Carl Johanneson, may have risen sharply, but he retains a humble view of his status.
"I don't look at it like I'm the star. I tell people that although I'm the world champion, all that matters is I'm fit and that I'm fighting. Sometimes they don't believe me," he said.
"Boxing's all I've ever wanted to do. I don't put any pressure on myself going into a fight because I'm not afraid to lose - I lost a couple of times early in my career.
"My attitude is that I'd rather be boxing and training than getting up to work in the morning, so for me I've got the best job in the world."
Walsh, who ended nine of his 13 victories early, is only too happy to be regarded as a rank outsider.
"It's always been my dream to be a world champion and now I've been given my opportunity, which I'm grateful for," he said.
"I find it amusing that people are calling it a mis-match and I hope it carries on like that, because it takes all the pressure off me.
"I'm not expected to do anything and the pressure's on Ricky, but I still believe I can win. It's not ideal that it's come now, but it's an opportunity I intend taking.
"It's win-win - if I win I get a world title, if I lose well no one expected me to win. Ricky lost early in his career and look where he is now."